Exploring cost-effective and efficient catalysts for oxygen reduction reaction(ORR)poses a significant challenge,espe-cially in the pursuit of alternatives to precious metals like platinum.Significant advancements hav...Exploring cost-effective and efficient catalysts for oxygen reduction reaction(ORR)poses a significant challenge,espe-cially in the pursuit of alternatives to precious metals like platinum.Significant advancements have driven electrochem-ists to develop efficient ORR catalysts using abundant materials,particularly iron(Fe)-based,known for their exceptional performance in ORR.While the crucial function of Fe in boosting ORR catalytic activity is recognized,the connection between material attributes and catalytic performance remains enigmatic.Understanding the dynamic processes involved in oxygen electrocatalysis is paramount for designing precious-metals-free ORR electrocatalysts.Mössbauer spectroscopy stands out as a powerful technique for deciphering the structural characteristics of Fe species in catalysis,facilitating the identification of active sites and the clarification of catalytic mechanisms.By showcasing noteworthy case studies within this review,we demonstrate the application of in-situ/operando 57Fe Mössbauer spectroscopy across diverse Fe-involved materials in ORR catalysis.This sheds light on various aspects of ORR catalysis,such as identifying active sites,assessing stability,and understanding the reaction mechanism.Our inquiry drives towards the opportunities and hurdles associ-ated with Mössbauer spectroscopy,unveiling potential breakthroughs and avenues for enhancement within this pivotal research realm.展开更多
Water electrolysis is pivotal for converting renewable energy into clean hydrogen fuel,addressing global energy demand sustainably.However,the development of highly efficient and cost-effective catalysts for the oxyge...Water electrolysis is pivotal for converting renewable energy into clean hydrogen fuel,addressing global energy demand sustainably.However,the development of highly efficient and cost-effective catalysts for the oxygen evolution reaction(OER)remains a significant challenge,particularly at the industrial scale.This report explores a newly discovered pathway,the oxide path mechanism(OPM) for OER-mechanism involving the oxide formation and evolution during the reaction,emphasizing its potential to overcome existing limitations.OPM enables direct O-O coupling without oxygen vacancies,offering superior stability.We detail both classical and innovative in-situ characterization techniques that are central to unraveling the OER mechanism.The advanced in-situ electrochemical techniques,such as inductively coupled plasma mass spectroscopy,X-ray photoelectron spectroscopy,and Mössbauer spectroscopy,coupled with in-situ structural analyses,provide crucial insights into the catalyst surface,the electrode-electrolyte interface and the kinetics of OER.This review provides a systematic analysis integrating classical electrochemical methods with advanced in-situ/operando techniques,specifically focusing on understanding OPM.While numerous studies have examined individual characterization methods,this study systematically integrates traditional electrochemical approaches with in-situ and operando techniques,offering critical insights into their complementary roles in elucidating reaction pathways.The integration of these methodologies provides unprecedented understanding of catalyst behavior under operational conditions,guiding the rational design of next-generation OER catalysts.Furthermore,we discuss essential standardized test toolkits and protocols,such as those for rotating disk electrode and membrane electrode assembly,which are vital for ensuring reproducibility and scalability in OER catalyst research.展开更多
Selective reduction of N_(2)O by CO under excess O_(2) was effectively catalyzed by Fe(0.9 wt%)-exchangedβzeolite(Fe0.9β)in the temperature range of 250–500°C.Kinetic experiments showed that the apparent activ...Selective reduction of N_(2)O by CO under excess O_(2) was effectively catalyzed by Fe(0.9 wt%)-exchangedβzeolite(Fe0.9β)in the temperature range of 250–500°C.Kinetic experiments showed that the apparent activation energy for N_(2)O reduction with CO was lower than that for the direct N_(2)O decomposition,and the rate of N_(2)O reduction with CO at 300℃ was 16 times higher than that for direct N_(2)O decomposition.Reaction order analyses showed that CO and N_(2)O were involved in the kinetically important step,while O_(2) was not involved in the important step.At 300℃,the rate of CO oxidation with 0.1%N_(2)O was two times higher than that of CO oxidation with 10%O_(2).This quantitatively demonstrates the preferential oxidation of CO by N_(2)O under excess O_(2) over Fe0.9β.Operando/in-situ diffuse reflectance ultraviolet-visible spectroscopy showed a redox-based catalytic cycle;α-Fe-O species are reduced by CO to give CO_(2) and reduced Fe species,which are then re-oxidized by N_(2)O to regenerate theα-Fe-O species.The initial rate for the regeneration ofα-Fe-O species under 0.1%N_(2)O was four times higher than that under 10%O_(2).This result shows quantitative evidence on the higher reactivity of N_(2)O than O_(2) for the regeneration ofα-Fe-O intermediates,providing a fundamental reason why the Fe0.9βcatalyst selectively promotes the CO+N_(2)O reaction under excess O_(2) rather than the undesired side reaction of CO+O_(2).The mechanistic model was verified by the results of in-situ Fe K-edge X-ray absorption spectroscopy.展开更多
Nowadays,in-situ/operando characterization becomes one of the most powerful as well as available means to monitor intricate reactions and investigate energy-storage mechanisms within advanced batteries.The new applica...Nowadays,in-situ/operando characterization becomes one of the most powerful as well as available means to monitor intricate reactions and investigate energy-storage mechanisms within advanced batteries.The new applications and novel devices constructed in recent years are necessary to be reviewed for inspiring subsequent studies.Hence,we summarize the progress of in-situ/operando techniques employed in rechargeable batteries.The members of this large family are divided into three sections for introduction,including bulk material,electrolyte/electrode interface and gas evolution.In each part,various energy-storage systems are mentioned and the related experimental details as well as data analysis are discussed.The simultaneous strategies of various in-situ methods are highlighted as well.Finally,current challenges and potential solutions are concluded towards the rising influence and enlarged appliance of in-situ/operando techniques in the battery research.展开更多
The increasing demands of multifunctional organic electronics require advanced organic semiconducting materials to be developed and significant improvements to be made to device performance. Thus, it is necessary to g...The increasing demands of multifunctional organic electronics require advanced organic semiconducting materials to be developed and significant improvements to be made to device performance. Thus, it is necessary to gain an in-depth understanding of the film growth process, electronic states, and dynamic structure-property relationship under realistic operation conditions, which can be obtained by in-situ/operando characterization techniques for organic devices. Here, the up-todate developments in the in-situ/operando optical, scanning probe microscopy, and spectroscopy techniques that are employed for studies of film morphological evolution, crystal structures, semiconductor-electrolyte interface properties, and charge carrier dynamics are described and summarized. These advanced technologies leverage the traditional static characterizations into an in-situ and interactive manipulation of organic semiconducting films and devices without sacrificing the resolution, which facilitates the exploration of the intrinsic structure-property relationship of organic materials and the optimization of organic devices for advanced applications.展开更多
The catalytic conversion of CO_(2) to fuels or chemicals is considered to be an effective pathway to mitigate the greenhouse effect. To develop new types of efficient and durable catalysts, it is critical to identify ...The catalytic conversion of CO_(2) to fuels or chemicals is considered to be an effective pathway to mitigate the greenhouse effect. To develop new types of efficient and durable catalysts, it is critical to identify the catalytic active sites, surface intermediates, and reaction mechanisms to reveal the relationship between the active sites and catalytic performance. However, the structure of a heterogeneous catalyst usually dynamically changes during reaction, bringing a great challenge for the identification of catalytic active sites and reaction pathways. Therefore, in-situ/operando techniques have been employed to real-time monitor the dynamic evolution of the structure of active sites under actual reaction conditions to precisely build the structure–function relationship. Here, we review the recent progress in the application of various in-situ/operando techniques in identifying active sites for catalytic conversion of CO_(2) over heterogeneous catalysts. We systematically summarize the applications of various optical and X-ray spectroscopy techniques, including Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and X-ray absorption spectroscopy (XAS), in identifying active sites and determining reaction mechanisms of the CO_(2) thermochemical conversion with hydrogen and light alkanes over heterogeneous catalysts. Finally, we discuss challenges and opportunities for the development of in-situ characterization in the future to further enlarge the capability of these powerful techniques.展开更多
Accelerating the redox conversion of lithium polysulfides(Li PSs)with electrocatalysts has been regarded as an effective avenue to surmount the shuttle effect and realize high-performance lithium-sulfur(Li-S)batteries...Accelerating the redox conversion of lithium polysulfides(Li PSs)with electrocatalysts has been regarded as an effective avenue to surmount the shuttle effect and realize high-performance lithium-sulfur(Li-S)batteries.However,the complicated reaction process,especially the real-time evolution of sulfur-containing species and electrocatalysts under working conditions,has brought great difficulties in the explicit understanding of reaction mechanism of Li-S batteries,thereby severely hampering the design of highly efficient electrocatalysts.Therefore,a crucial prerequisite for correctly identifying the reaction mechanism is an in-depth analysis of the dynamic evolution of reaction intermediates and their structure-performance relationships.In this review,we comprehensively summarized the most recent progress in the dynamic behaviors of Li PSs and electrocatalysts of Li-S batteries under working conditions in conjunction with closely related in-situ/operando characterizations to recognize the realtime evolution of phase,composition,and atomic/electronic structure,thereby unraveling the corresponding catalytic mechanism.In addition,the major challenges and unexplored issues of catalytic conversion of Li PSs were summarized and discussed,aiming to provide perspectives into the development of highly efficient electrocatalysts in Li-S chemistry.Based on this review,we believe that reasonable regulation of reconstruction behaviors can achieve satisfactory electrocatalysts with high catalytic activity,accelerating the development of green energy.展开更多
In-situ tensile tests were conducted on a chemically corroded third-generation single-crystal superalloy DD9 at 980 and 1100℃.The phase transformation in the surface areas during the tensile process was analyzed usin...In-situ tensile tests were conducted on a chemically corroded third-generation single-crystal superalloy DD9 at 980 and 1100℃.The phase transformation in the surface areas during the tensile process was analyzed using field emission scanning electron microscope,energy dispersive X-ray spectroscope,electron probe X-ray microanalysis,and transmission electron microscope.The phase transformation mechanism on the surface and the influence mechanism were studied through observation and dynamic calculation.During tensile tests at elevated temperatures,chemical corrosion promotes the precipitation of topologically close-packed(tcp)μphase andσphase on the alloy surface.Both the precipitation amount and size of these two phases on the surface at 1100℃are greater than those at 980℃.The precipitation of tcp phase on the alloy surface results in the formation of an influence layer on the surface area,and the distribution characteristics of alloying elements are significantly different from those of the substrate.The depth of the influence layer at 1100℃is greater than that at 980℃.The precipitation of tcp phase prompts the phase transition fromγphase toγ′phase around the tcp phase.展开更多
The effect of manganese sulfide(MnS)inclusions and gadolinium–sulfide(Gd–S)inclusions on the deformation behavior of steel matrix at different stages was studied by in-situ tensile experiments using a scanning elect...The effect of manganese sulfide(MnS)inclusions and gadolinium–sulfide(Gd–S)inclusions on the deformation behavior of steel matrix at different stages was studied by in-situ tensile experiments using a scanning electron microscopy(SEM)at room temperature.Two in-situ tensile experiments of tensile force along the elongation direction of inclusions and perpendicular to the elongation direction were conducted.The hole-induced nucleation mechanism of different tensile directions and inclusion types during the tensile deformation process was revealed.When the tensile direction of the steel without Gd was parallel to the forging elongation direction,the tensile strength was 454 MPa.Meanwhile,long strip MnS inclusions were broken and shed,forming long strip holes perpendicular to the fracture direction.When the tensile direction was perpendicular to the forging elongation direction,the gap between long strip MnS inclusions and the steel matrix was expanded into a long strip hole parallel to the fracture direction,and the tensile strength was 402 MPa.Anisotropy of the steel was induced by long strip MnS inclusions.In the steel with a total gadolinium(T.Gd)content of 730 ppm,the tensile strength was 468 MPa when the tensile direction was parallel to the forging elongation direction.The tensile strength of the steel was 446MPa when the tensile direction was perpendicular to the forging elongation direction.The addition of Gd in the steel was beneficial to improve the tensile properties of the steel and reduce the anisotropy of the steel.展开更多
To address the problems with catalytic degradation,such as poisoning and inactivation,a simple and efficient gas purging regeneration technique was developed for iron-based catalyst in-situ regeneration.Specifically,t...To address the problems with catalytic degradation,such as poisoning and inactivation,a simple and efficient gas purging regeneration technique was developed for iron-based catalyst in-situ regeneration.Specifically,the effects of carrier gas types,regeneration temperatures,and granular activated carbon(GAC)addition on iron-based catalyst regeneration were investigated.The Fe_(3)O_(4)/𝛾-Al_(2)O_(3) regenerated at 550°C with additional GAC and 15%water vapor exhibited the optimal degradation efficiency towards polychlorinated biphenyls(PCBs),with an increase from 41.2%to 93.5%,compared with non-regenerated Fe_(3)O_(4)/𝛾-Al_(2)O_(3).In addition,the 60-hour stability test revealed a well-recovered catalytic activity.During the Fe_(3)O_(4)/𝛾-Al_(2)O_(3) regeneration,the coke on the catalyst surface was oxidized and removed in the form of CO_(2),and meanwhile the oxidized Fe(III)was reduced into Fe(II)in the catalyst.This study provides a safe and efficient iron-based catalyst regeneration technology for PCB off-gas degradation and reveals the catalytic activity recovery mechanism during catalyst regeneration.展开更多
Despite significant progress in fuel cell technology,its large-scale industrial application is still challenged by the frequently encountered performance failure during long-term operation.Clarifying the failure mecha...Despite significant progress in fuel cell technology,its large-scale industrial application is still challenged by the frequently encountered performance failure during long-term operation.Clarifying the failure mechanism is the key to extending the lifecycle and enhancing stability.Herein,we have developed a time and space resolved multi-field characterization,including electrochemical impedance spectroscopy,to unveil its underlying mechanism.With this operando and non-destructive characterization,the dynamic evolution of the internal mass transport,heat,and electricity field distribution is fully depicted within an industrial-scale fuel cell in operation.Thus,it is revealed that hydrogen starvation occurs in the outlet region due to the excessive hydrogen consumption during the loading-down process.This can induce local low current density and carbon corrosion,which may subsequently cause severe damage to the structure of the catalyst layer and membrane,ultimately leading to performance failure.With this understanding,we further identify a descriptor for early diagnosis to prevent any potential degradation.The methodology is of significance,which can bring fuel cell technology a step further towards industrial applications.展开更多
In-situ stress is a key parameter for underground mine design and rock stability analysis.The borehole overcoring technique is widely used for in-situ stress measurement,but the rheological recovery deformation of roc...In-situ stress is a key parameter for underground mine design and rock stability analysis.The borehole overcoring technique is widely used for in-situ stress measurement,but the rheological recovery deformation of rocks after stress relief introduces errors.To improve accuracy,this study proposes an in-situ stress solution theory that incorporates time-dependent stress relief effects.Triaxial stepwise loadingunloading rheological tests on granite and siltstone established quantitative relationships between instantaneous elastic recovery and viscoelastic recovery under different stress levels,confirming their impact on measurement accuracy.By integrating a dual-class elastic deformation recovery model,an improved in-situ stress solution theory was derived.Additionally,accounting for the nonlinear characteristics of rock masses,a determination method for time-dependent nonlinear mechanical parameters was proposed.Based on the CSIRO hollow inclusion strain cell,time-dependent strain correction equations and long-term confining pressure calibration equations were formulated.Finally,the proposed theory was successfully applied at one iron mine(736 m depth)in Xinjiang,China,and one coal mine(510 m depth)in Ningxia,China.Compared to classical theory,the calculated mean stress values showed accuracy improvements of 6.0%and 9.4%,respectively,validating the applicability and reliability of the proposed theory.展开更多
Rare earth(RE)Y-type zeolite was synthesized in situ by acidic co-hydrolysis route and hydrothermal method.The key process parameters were optimized based on the RE utilization rate.The effect of inducing a rotating p...Rare earth(RE)Y-type zeolite was synthesized in situ by acidic co-hydrolysis route and hydrothermal method.The key process parameters were optimized based on the RE utilization rate.The effect of inducing a rotating packed bed(RPB)in premixing and crystallization on crystallinity and RE utilization rate was further investigated.The results indicate that lanthanide(La)cations are successfully introduced into the sodalite cage of Y-type zeolite.The optimized conditions are that the molar ratio of Si/La is 150,premixing for 5 h,crystallization at 90℃ for 18 h,and calcination at 550℃ for 3.5 h.At this stage,the RE utilization rate reaches 74.5%.Compared with the conventional stirred tank reactor(STR),RPB can effectively shorten the premixing time and crystallization time by 4.3 h and 6 h,improve the crystallinity by 23%and RE utilization rate by 7.5%.The RE utilization rate is more than 80%by RPB,surpassing the effectiveness of using the one-exchange one-calcination process in the traditional liquid ion exchange process.It is expected to provide a reference for the in-situ efficient and green synthesis of RE zeolite.展开更多
Lithium metal batteries(LMBs)represent a promising solution for next-generation energy storage due to their high energy density,but the growth of lithium dendrites presents significant challenges to their performance ...Lithium metal batteries(LMBs)represent a promising solution for next-generation energy storage due to their high energy density,but the growth of lithium dendrites presents significant challenges to their performance and safety.This review provides a comprehensive overview of the mechanisms behind lithium dendrite formation and the role of in situ/operando observation and phase field simulation in understanding and mitigating this issue,The key driving factors of dendrite growth,such as lithium-ion flux heterogeneity,surface defects,and localized stress,are explored through advanced experimental techniques,which enable real-time visualization of dendrite nucleation and growth dynamics.Complementarily,phase field simulations provide insights into subsurface and temporal evolution of dendrites by modeling thermodynamic and kinetic processes,while machine learning techniques optimize simulation accuracy through data-driven parameter refinement.The integration of experimental observations with simulation models holds great potential in improving understanding and predictive capabilities.Despite ongoing progress,challenges remain in resolving technical limitations in observation techniques,improving computational efficiency,and fostering interdisciplinary collaboration.This review highlights the synergy between experimental and computational strategies in advancing the development of LMBs and calls for continued research to overcome existing hurdles and unlock the full potential of lithium metal anodes.展开更多
The main purpose of using geothermal energy piles(GEPs)is to enable the exploitation of geothermal energy for meeting the heating/cooling demands of buildings efficiently.However,the installation process of convention...The main purpose of using geothermal energy piles(GEPs)is to enable the exploitation of geothermal energy for meeting the heating/cooling demands of buildings efficiently.However,the installation process of conventional GEPs is inconvenient compared with that of traditional foundation piles.The pre-bored grouted planted geothermal energy pile(PGP GEP)is an innovative technology to simplify the installation process.Most investigations of in-situ experiments for conventional GEPs have focused on summer conditions.An in-situ test for a PGP GEP was conducted to analyze the temperature changes and thermo-mechanical characteristics under winter conditions.The results show that the average temperature of the pile decreased by 5.1℃,and the pile exhibited a general trend of high temperatures at both ends and low temperatures in the middle.In mechanics,strong pile end restraints resulted in smaller observed axial strain and higher axial thermal-induced force in the pile ends than at the middle of the pile.展开更多
Waterborne acrylic coatings are widely utilized due to their cost-effectiveness,high transparency,strong resistance to weather and chemicals,impressive mechanical properties,and excellent adhesion to various substrate...Waterborne acrylic coatings are widely utilized due to their cost-effectiveness,high transparency,strong resistance to weather and chemicals,impressive mechanical properties,and excellent adhesion to various substrates.In these coatings,a reactive emulsifier containing phosphate groups can be integrated into the molecular chain during polymerization,which enhances the coating's compactness and corrosion resistance.This work focuses on the synthesis of styrene-butyl acrylate(St-BA)latex and methyl methacrylate-butyl acrylate(MMA-BA)latex using the reactive phosphate emulsifier ANPEO_(10)-P_(1) through seed emulsion polymerization,achieving a conversion rate of approximately 99%and a solid content close to 50%.The resulting coatings from St-BA and MMA-BA latexes demonstrated long-term corrosion protection for carbon steel and aluminum alloy due to in-situ phosphatization,effectively preventing flash rust.Notably,the MMA-BA coating exhibited remarkable durability,enduring immersion for up to 1224 h(51 d)on Q 235 carbon steel before reaching the failure threshold(|Z|0.01 Hz£106Ω·cm^(2))on Q 235 carbon steel.On 5052 aluminum alloy,the St-BA coating maintained|Z|0.01 Hz>10^(8)Ω·cm^(2) for 480 h(20 d).Furthermore,the corrosion resistance of St-BA and MMA BA coatings on Q 235 steel sheet and 5052 aluminum alloy surpassed that of commercially available MMA-BA and St BA coatings after immersion in a 3.5 wt%NaCl aqueous solution.This work also delves into the anticorrosion mechanism of MMA-BA and St-BA coatings.展开更多
Cold deformation treatment of Cu-bearing stainless steel through a cold rolling process combined with electric pulse treatment(EPT)can significantly improve the microstructure and formability of cold-rolled Cu-bearing...Cold deformation treatment of Cu-bearing stainless steel through a cold rolling process combined with electric pulse treatment(EPT)can significantly improve the microstructure and formability of cold-rolled Cu-bearing stainless steel.The microstructure after EPT was characterized by scanning electron microscopy,transmission electron microscopy,and in-situ tensile testing.It is found that compared with conventional heat treatment,EPT process can significantly promote the nucleation rate and mobility at grain boundaries of the deformed samples,greatly accelerating the recovery and static recrystallization of Cu-bearing stainless steel samples at lower temperatures and contributing to the recovery of anisotropy and the re-molding of deformed samples.Microstructural characterization and theoretical analyses show that the rapid recrystallization during EPT process is caused not only by Joule heating effects but also by non-thermal effects that accelerate grain boundary migration and dislocation destruction and regeneration.In addition,EPT process significantly accelerated the nucleation and precipitation growth of Cu-rich phase.The coarsening of Cu-rich phase during EPT process is due to not only the high vacancy diffusion coefficient under the action of the electric pulse but also the increase in the vacancy diffusion flux induced by the electromigration in the process of the electric pulse.展开更多
As atmospheric CO_(2) concentration continues to rise,carbon capture and utilization(CCU)technology has emerged as a critical strategy toward achieving carbon neutrality.CCU offers a dual advantage of mitigating CO_(2...As atmospheric CO_(2) concentration continues to rise,carbon capture and utilization(CCU)technology has emerged as a critical strategy toward achieving carbon neutrality.CCU offers a dual advantage of mitigating CO_(2) emissions while producing value-added chemicals and fuels.However,conventional CCU strategies typically decouple the CO_(2) capture and electrochemical conversion processes,resulting in increased system complexity,higher energy demands,and limited economic viability.Building an integrated system of CO_(2) capture and in-situ electroreduction can bridge the technological gap,reduce costs,and ultimately enhance carbon cycle efficiency.In this review,we highlight recent advances in CO_(2) capture and in-situ electroreduction technologies.We first evaluate the strengths and limitations of conventional CCU technologies and the emerging CO_(2) capture and direct utilization technologies.Subsequently,we summarize the breakthroughs in multifunctional catalyst systems and key catalyst optimization strategies,and analyze the mechanisms behind the performance improvement.Meanwhile,we also discuss the application progress of in-situ techniques and theoretical calculations in CO_(2) capture and in-situ electroreduction.Finally,we outline the unresolved scientific and engineering challenges and propose future research directions to accelerate the development of CO_(2) capture and in-situ electroreduction.展开更多
In-situ heating conversion is the most practical recovery method for lacustrine low-to-medium maturity shale oil.However,the energy output-input ratio must exceed the economic threshold to achieve commercial developme...In-situ heating conversion is the most practical recovery method for lacustrine low-to-medium maturity shale oil.However,the energy output-input ratio must exceed the economic threshold to achieve commercial development.This paper systematically investigates the mechanism of super-rich accumulation of organic matter in continental shale,sweet spot evaluation,optimal heating windows,and appropriate well types and patterns from the perspectives of enhancing energy output and reducing energy input.(1)The super-rich accumulation of organic matter in lacustrine shale is primarily controlled by the intensity,frequency,and preservation of external material inputs,and is related to moderate volcanic and hydrothermal activities,marine transgressions,with total organic carbon content greater than or equal to 6%.(2)The quality of organic-rich intervals is related to the type of source material and hydrocarbon generation potential.The in-situ conversion-derived hydrocarbon quality index(HQI)is established,and the zones exhibiting HQI>450 are defined as sweet spots.(3)Considering the characteristics of the organic matter conversion material field and seepage field,the temperature interval 300-370℃is recommended as the optimal heating window for the Chang 7_(3)sub-member of the Triassic Yanchang Formation in the Ordos Basin.Based on the advantages of thermal conductivity,permeability,and hydrocarbon expulsion efficiency along the bedding direction during in-situ heating,the“horizontal well heating+vertical well development”scheme is proposed,which has demonstrated significant enhancement in both recovery factor and energy output-input ratio,making it the optimal in-situ conversion process.The research findings provide a theoretical and technical foundation for the economical and efficient development of low-to-medium maturity shale oil.展开更多
基金financially supported by the National Natural Science Foundation of China (22350410386,W2412116,22375200,U22A202175,21961142006)。
文摘Exploring cost-effective and efficient catalysts for oxygen reduction reaction(ORR)poses a significant challenge,espe-cially in the pursuit of alternatives to precious metals like platinum.Significant advancements have driven electrochem-ists to develop efficient ORR catalysts using abundant materials,particularly iron(Fe)-based,known for their exceptional performance in ORR.While the crucial function of Fe in boosting ORR catalytic activity is recognized,the connection between material attributes and catalytic performance remains enigmatic.Understanding the dynamic processes involved in oxygen electrocatalysis is paramount for designing precious-metals-free ORR electrocatalysts.Mössbauer spectroscopy stands out as a powerful technique for deciphering the structural characteristics of Fe species in catalysis,facilitating the identification of active sites and the clarification of catalytic mechanisms.By showcasing noteworthy case studies within this review,we demonstrate the application of in-situ/operando 57Fe Mössbauer spectroscopy across diverse Fe-involved materials in ORR catalysis.This sheds light on various aspects of ORR catalysis,such as identifying active sites,assessing stability,and understanding the reaction mechanism.Our inquiry drives towards the opportunities and hurdles associ-ated with Mössbauer spectroscopy,unveiling potential breakthroughs and avenues for enhancement within this pivotal research realm.
基金funded by the EU H2020 Marie Skłodowska-Curie Fellowship (1439425)the National Natural Science Foundation of China (No. 52171199 and 22479011)
文摘Water electrolysis is pivotal for converting renewable energy into clean hydrogen fuel,addressing global energy demand sustainably.However,the development of highly efficient and cost-effective catalysts for the oxygen evolution reaction(OER)remains a significant challenge,particularly at the industrial scale.This report explores a newly discovered pathway,the oxide path mechanism(OPM) for OER-mechanism involving the oxide formation and evolution during the reaction,emphasizing its potential to overcome existing limitations.OPM enables direct O-O coupling without oxygen vacancies,offering superior stability.We detail both classical and innovative in-situ characterization techniques that are central to unraveling the OER mechanism.The advanced in-situ electrochemical techniques,such as inductively coupled plasma mass spectroscopy,X-ray photoelectron spectroscopy,and Mössbauer spectroscopy,coupled with in-situ structural analyses,provide crucial insights into the catalyst surface,the electrode-electrolyte interface and the kinetics of OER.This review provides a systematic analysis integrating classical electrochemical methods with advanced in-situ/operando techniques,specifically focusing on understanding OPM.While numerous studies have examined individual characterization methods,this study systematically integrates traditional electrochemical approaches with in-situ and operando techniques,offering critical insights into their complementary roles in elucidating reaction pathways.The integration of these methodologies provides unprecedented understanding of catalyst behavior under operational conditions,guiding the rational design of next-generation OER catalysts.Furthermore,we discuss essential standardized test toolkits and protocols,such as those for rotating disk electrode and membrane electrode assembly,which are vital for ensuring reproducibility and scalability in OER catalyst research.
文摘Selective reduction of N_(2)O by CO under excess O_(2) was effectively catalyzed by Fe(0.9 wt%)-exchangedβzeolite(Fe0.9β)in the temperature range of 250–500°C.Kinetic experiments showed that the apparent activation energy for N_(2)O reduction with CO was lower than that for the direct N_(2)O decomposition,and the rate of N_(2)O reduction with CO at 300℃ was 16 times higher than that for direct N_(2)O decomposition.Reaction order analyses showed that CO and N_(2)O were involved in the kinetically important step,while O_(2) was not involved in the important step.At 300℃,the rate of CO oxidation with 0.1%N_(2)O was two times higher than that of CO oxidation with 10%O_(2).This quantitatively demonstrates the preferential oxidation of CO by N_(2)O under excess O_(2) over Fe0.9β.Operando/in-situ diffuse reflectance ultraviolet-visible spectroscopy showed a redox-based catalytic cycle;α-Fe-O species are reduced by CO to give CO_(2) and reduced Fe species,which are then re-oxidized by N_(2)O to regenerate theα-Fe-O species.The initial rate for the regeneration ofα-Fe-O species under 0.1%N_(2)O was four times higher than that under 10%O_(2).This result shows quantitative evidence on the higher reactivity of N_(2)O than O_(2) for the regeneration ofα-Fe-O intermediates,providing a fundamental reason why the Fe0.9βcatalyst selectively promotes the CO+N_(2)O reaction under excess O_(2) rather than the undesired side reaction of CO+O_(2).The mechanistic model was verified by the results of in-situ Fe K-edge X-ray absorption spectroscopy.
基金supported by the Natural Science Foundation of Jiangsu Province,China(BK20170630)the National Natural Science Foundation of China(51802149 and U1801251)+1 种基金the Fundamental Research Funds for the Central Universitiesthe Nanjing University Technology Innovation Fund Project。
文摘Nowadays,in-situ/operando characterization becomes one of the most powerful as well as available means to monitor intricate reactions and investigate energy-storage mechanisms within advanced batteries.The new applications and novel devices constructed in recent years are necessary to be reviewed for inspiring subsequent studies.Hence,we summarize the progress of in-situ/operando techniques employed in rechargeable batteries.The members of this large family are divided into three sections for introduction,including bulk material,electrolyte/electrode interface and gas evolution.In each part,various energy-storage systems are mentioned and the related experimental details as well as data analysis are discussed.The simultaneous strategies of various in-situ methods are highlighted as well.Finally,current challenges and potential solutions are concluded towards the rising influence and enlarged appliance of in-situ/operando techniques in the battery research.
基金support from Natural Science Foundation of Jiangsu Province (grant number BK20211507)National Natural Science Foundation of China (grant number 61774080)the start-up funds from Changzhou University。
文摘The increasing demands of multifunctional organic electronics require advanced organic semiconducting materials to be developed and significant improvements to be made to device performance. Thus, it is necessary to gain an in-depth understanding of the film growth process, electronic states, and dynamic structure-property relationship under realistic operation conditions, which can be obtained by in-situ/operando characterization techniques for organic devices. Here, the up-todate developments in the in-situ/operando optical, scanning probe microscopy, and spectroscopy techniques that are employed for studies of film morphological evolution, crystal structures, semiconductor-electrolyte interface properties, and charge carrier dynamics are described and summarized. These advanced technologies leverage the traditional static characterizations into an in-situ and interactive manipulation of organic semiconducting films and devices without sacrificing the resolution, which facilitates the exploration of the intrinsic structure-property relationship of organic materials and the optimization of organic devices for advanced applications.
基金Authors acknowledge the financial support from the National Natural Science Foundation of China(NSFC)under Grant No.21978148 and 21808120.
文摘The catalytic conversion of CO_(2) to fuels or chemicals is considered to be an effective pathway to mitigate the greenhouse effect. To develop new types of efficient and durable catalysts, it is critical to identify the catalytic active sites, surface intermediates, and reaction mechanisms to reveal the relationship between the active sites and catalytic performance. However, the structure of a heterogeneous catalyst usually dynamically changes during reaction, bringing a great challenge for the identification of catalytic active sites and reaction pathways. Therefore, in-situ/operando techniques have been employed to real-time monitor the dynamic evolution of the structure of active sites under actual reaction conditions to precisely build the structure–function relationship. Here, we review the recent progress in the application of various in-situ/operando techniques in identifying active sites for catalytic conversion of CO_(2) over heterogeneous catalysts. We systematically summarize the applications of various optical and X-ray spectroscopy techniques, including Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and X-ray absorption spectroscopy (XAS), in identifying active sites and determining reaction mechanisms of the CO_(2) thermochemical conversion with hydrogen and light alkanes over heterogeneous catalysts. Finally, we discuss challenges and opportunities for the development of in-situ characterization in the future to further enlarge the capability of these powerful techniques.
基金supported by the National Natural Science Foundation of China(22309019,12275189,22472111,and 11832007)the Natural Science Foundation of Sichuan Province(2023NSFSC1130)+1 种基金the Sichuan Province Support Tianfu Distinguished Scientist Program(126608533369)the Suzhou Science and Technology Project Prospective Application Research Program(SYG202109)。
文摘Accelerating the redox conversion of lithium polysulfides(Li PSs)with electrocatalysts has been regarded as an effective avenue to surmount the shuttle effect and realize high-performance lithium-sulfur(Li-S)batteries.However,the complicated reaction process,especially the real-time evolution of sulfur-containing species and electrocatalysts under working conditions,has brought great difficulties in the explicit understanding of reaction mechanism of Li-S batteries,thereby severely hampering the design of highly efficient electrocatalysts.Therefore,a crucial prerequisite for correctly identifying the reaction mechanism is an in-depth analysis of the dynamic evolution of reaction intermediates and their structure-performance relationships.In this review,we comprehensively summarized the most recent progress in the dynamic behaviors of Li PSs and electrocatalysts of Li-S batteries under working conditions in conjunction with closely related in-situ/operando characterizations to recognize the realtime evolution of phase,composition,and atomic/electronic structure,thereby unraveling the corresponding catalytic mechanism.In addition,the major challenges and unexplored issues of catalytic conversion of Li PSs were summarized and discussed,aiming to provide perspectives into the development of highly efficient electrocatalysts in Li-S chemistry.Based on this review,we believe that reasonable regulation of reconstruction behaviors can achieve satisfactory electrocatalysts with high catalytic activity,accelerating the development of green energy.
文摘In-situ tensile tests were conducted on a chemically corroded third-generation single-crystal superalloy DD9 at 980 and 1100℃.The phase transformation in the surface areas during the tensile process was analyzed using field emission scanning electron microscope,energy dispersive X-ray spectroscope,electron probe X-ray microanalysis,and transmission electron microscope.The phase transformation mechanism on the surface and the influence mechanism were studied through observation and dynamic calculation.During tensile tests at elevated temperatures,chemical corrosion promotes the precipitation of topologically close-packed(tcp)μphase andσphase on the alloy surface.Both the precipitation amount and size of these two phases on the surface at 1100℃are greater than those at 980℃.The precipitation of tcp phase on the alloy surface results in the formation of an influence layer on the surface area,and the distribution characteristics of alloying elements are significantly different from those of the substrate.The depth of the influence layer at 1100℃is greater than that at 980℃.The precipitation of tcp phase prompts the phase transition fromγphase toγ′phase around the tcp phase.
基金supported by the National Key R&D Program of China (No.2023YFB3709900)the National Nature Science Foundation of China (Nos.U22A20171,52204333,and 52174293)+1 种基金the Beijing Natural Science Foundation (No.2242034)the High Steel Center (HSC) at Yanshan University and North China University of Technology
文摘The effect of manganese sulfide(MnS)inclusions and gadolinium–sulfide(Gd–S)inclusions on the deformation behavior of steel matrix at different stages was studied by in-situ tensile experiments using a scanning electron microscopy(SEM)at room temperature.Two in-situ tensile experiments of tensile force along the elongation direction of inclusions and perpendicular to the elongation direction were conducted.The hole-induced nucleation mechanism of different tensile directions and inclusion types during the tensile deformation process was revealed.When the tensile direction of the steel without Gd was parallel to the forging elongation direction,the tensile strength was 454 MPa.Meanwhile,long strip MnS inclusions were broken and shed,forming long strip holes perpendicular to the fracture direction.When the tensile direction was perpendicular to the forging elongation direction,the gap between long strip MnS inclusions and the steel matrix was expanded into a long strip hole parallel to the fracture direction,and the tensile strength was 402 MPa.Anisotropy of the steel was induced by long strip MnS inclusions.In the steel with a total gadolinium(T.Gd)content of 730 ppm,the tensile strength was 468 MPa when the tensile direction was parallel to the forging elongation direction.The tensile strength of the steel was 446MPa when the tensile direction was perpendicular to the forging elongation direction.The addition of Gd in the steel was beneficial to improve the tensile properties of the steel and reduce the anisotropy of the steel.
基金supported by the Fundamental Research Funds for the Central Publicinterest Scientific Institution(No.2024YSKY-44)the National Key R&D Program of China(No.2023YFC3708003).
文摘To address the problems with catalytic degradation,such as poisoning and inactivation,a simple and efficient gas purging regeneration technique was developed for iron-based catalyst in-situ regeneration.Specifically,the effects of carrier gas types,regeneration temperatures,and granular activated carbon(GAC)addition on iron-based catalyst regeneration were investigated.The Fe_(3)O_(4)/𝛾-Al_(2)O_(3) regenerated at 550°C with additional GAC and 15%water vapor exhibited the optimal degradation efficiency towards polychlorinated biphenyls(PCBs),with an increase from 41.2%to 93.5%,compared with non-regenerated Fe_(3)O_(4)/𝛾-Al_(2)O_(3).In addition,the 60-hour stability test revealed a well-recovered catalytic activity.During the Fe_(3)O_(4)/𝛾-Al_(2)O_(3) regeneration,the coke on the catalyst surface was oxidized and removed in the form of CO_(2),and meanwhile the oxidized Fe(III)was reduced into Fe(II)in the catalyst.This study provides a safe and efficient iron-based catalyst regeneration technology for PCB off-gas degradation and reveals the catalytic activity recovery mechanism during catalyst regeneration.
基金supported by the National Key R&D Program of China[2023YFB4006100]。
文摘Despite significant progress in fuel cell technology,its large-scale industrial application is still challenged by the frequently encountered performance failure during long-term operation.Clarifying the failure mechanism is the key to extending the lifecycle and enhancing stability.Herein,we have developed a time and space resolved multi-field characterization,including electrochemical impedance spectroscopy,to unveil its underlying mechanism.With this operando and non-destructive characterization,the dynamic evolution of the internal mass transport,heat,and electricity field distribution is fully depicted within an industrial-scale fuel cell in operation.Thus,it is revealed that hydrogen starvation occurs in the outlet region due to the excessive hydrogen consumption during the loading-down process.This can induce local low current density and carbon corrosion,which may subsequently cause severe damage to the structure of the catalyst layer and membrane,ultimately leading to performance failure.With this understanding,we further identify a descriptor for early diagnosis to prevent any potential degradation.The methodology is of significance,which can bring fuel cell technology a step further towards industrial applications.
基金supported by the National Science and Technology Major Project of the Ministry of Science and Technology of China(No.2024ZD1700201)the National Natural Science Foundation of China(Nos.U2034206,51974014 and 51574014)+1 种基金the Guangdong Basic and Applied Basic Research Foundation(No.2024A1515011631)the National Key Research and Development Project of China(No.2022YFC3004601)。
文摘In-situ stress is a key parameter for underground mine design and rock stability analysis.The borehole overcoring technique is widely used for in-situ stress measurement,but the rheological recovery deformation of rocks after stress relief introduces errors.To improve accuracy,this study proposes an in-situ stress solution theory that incorporates time-dependent stress relief effects.Triaxial stepwise loadingunloading rheological tests on granite and siltstone established quantitative relationships between instantaneous elastic recovery and viscoelastic recovery under different stress levels,confirming their impact on measurement accuracy.By integrating a dual-class elastic deformation recovery model,an improved in-situ stress solution theory was derived.Additionally,accounting for the nonlinear characteristics of rock masses,a determination method for time-dependent nonlinear mechanical parameters was proposed.Based on the CSIRO hollow inclusion strain cell,time-dependent strain correction equations and long-term confining pressure calibration equations were formulated.Finally,the proposed theory was successfully applied at one iron mine(736 m depth)in Xinjiang,China,and one coal mine(510 m depth)in Ningxia,China.Compared to classical theory,the calculated mean stress values showed accuracy improvements of 6.0%and 9.4%,respectively,validating the applicability and reliability of the proposed theory.
基金supported by the NationalKey Research and Development Program of China(2023YFA1507701)National Natural Science Foundation of China(U22B6011,22288102)“Announcement and Challenge”Science and Technology Project of Xinjiang Uygur Autonomous Region(XJKJTJBGS-2023).
文摘Rare earth(RE)Y-type zeolite was synthesized in situ by acidic co-hydrolysis route and hydrothermal method.The key process parameters were optimized based on the RE utilization rate.The effect of inducing a rotating packed bed(RPB)in premixing and crystallization on crystallinity and RE utilization rate was further investigated.The results indicate that lanthanide(La)cations are successfully introduced into the sodalite cage of Y-type zeolite.The optimized conditions are that the molar ratio of Si/La is 150,premixing for 5 h,crystallization at 90℃ for 18 h,and calcination at 550℃ for 3.5 h.At this stage,the RE utilization rate reaches 74.5%.Compared with the conventional stirred tank reactor(STR),RPB can effectively shorten the premixing time and crystallization time by 4.3 h and 6 h,improve the crystallinity by 23%and RE utilization rate by 7.5%.The RE utilization rate is more than 80%by RPB,surpassing the effectiveness of using the one-exchange one-calcination process in the traditional liquid ion exchange process.It is expected to provide a reference for the in-situ efficient and green synthesis of RE zeolite.
基金the financial support of the National Natural Science Foundation of China(Nos.12172206 and 11972218)。
文摘Lithium metal batteries(LMBs)represent a promising solution for next-generation energy storage due to their high energy density,but the growth of lithium dendrites presents significant challenges to their performance and safety.This review provides a comprehensive overview of the mechanisms behind lithium dendrite formation and the role of in situ/operando observation and phase field simulation in understanding and mitigating this issue,The key driving factors of dendrite growth,such as lithium-ion flux heterogeneity,surface defects,and localized stress,are explored through advanced experimental techniques,which enable real-time visualization of dendrite nucleation and growth dynamics.Complementarily,phase field simulations provide insights into subsurface and temporal evolution of dendrites by modeling thermodynamic and kinetic processes,while machine learning techniques optimize simulation accuracy through data-driven parameter refinement.The integration of experimental observations with simulation models holds great potential in improving understanding and predictive capabilities.Despite ongoing progress,challenges remain in resolving technical limitations in observation techniques,improving computational efficiency,and fostering interdisciplinary collaboration.This review highlights the synergy between experimental and computational strategies in advancing the development of LMBs and calls for continued research to overcome existing hurdles and unlock the full potential of lithium metal anodes.
文摘The main purpose of using geothermal energy piles(GEPs)is to enable the exploitation of geothermal energy for meeting the heating/cooling demands of buildings efficiently.However,the installation process of conventional GEPs is inconvenient compared with that of traditional foundation piles.The pre-bored grouted planted geothermal energy pile(PGP GEP)is an innovative technology to simplify the installation process.Most investigations of in-situ experiments for conventional GEPs have focused on summer conditions.An in-situ test for a PGP GEP was conducted to analyze the temperature changes and thermo-mechanical characteristics under winter conditions.The results show that the average temperature of the pile decreased by 5.1℃,and the pile exhibited a general trend of high temperatures at both ends and low temperatures in the middle.In mechanics,strong pile end restraints resulted in smaller observed axial strain and higher axial thermal-induced force in the pile ends than at the middle of the pile.
基金Project(52373065)supported by the National Natural Science Foundation of ChinaProject(2220004002898)supported by the Zhuhai Industry University Research Cooperation and Basic and Applied Research Projects,China。
文摘Waterborne acrylic coatings are widely utilized due to their cost-effectiveness,high transparency,strong resistance to weather and chemicals,impressive mechanical properties,and excellent adhesion to various substrates.In these coatings,a reactive emulsifier containing phosphate groups can be integrated into the molecular chain during polymerization,which enhances the coating's compactness and corrosion resistance.This work focuses on the synthesis of styrene-butyl acrylate(St-BA)latex and methyl methacrylate-butyl acrylate(MMA-BA)latex using the reactive phosphate emulsifier ANPEO_(10)-P_(1) through seed emulsion polymerization,achieving a conversion rate of approximately 99%and a solid content close to 50%.The resulting coatings from St-BA and MMA-BA latexes demonstrated long-term corrosion protection for carbon steel and aluminum alloy due to in-situ phosphatization,effectively preventing flash rust.Notably,the MMA-BA coating exhibited remarkable durability,enduring immersion for up to 1224 h(51 d)on Q 235 carbon steel before reaching the failure threshold(|Z|0.01 Hz£106Ω·cm^(2))on Q 235 carbon steel.On 5052 aluminum alloy,the St-BA coating maintained|Z|0.01 Hz>10^(8)Ω·cm^(2) for 480 h(20 d).Furthermore,the corrosion resistance of St-BA and MMA BA coatings on Q 235 steel sheet and 5052 aluminum alloy surpassed that of commercially available MMA-BA and St BA coatings after immersion in a 3.5 wt%NaCl aqueous solution.This work also delves into the anticorrosion mechanism of MMA-BA and St-BA coatings.
基金supported by the National Natural Science Foundation of China(Nos.52305401 and 52475391)National Key Research and Development Program of China(2024YFB3714301)+1 种基金the Fundamental Research Program of Shanxi Province(202303011211004,TZLH20230818001)Engineering Research Center of the Ministry of Education.
文摘Cold deformation treatment of Cu-bearing stainless steel through a cold rolling process combined with electric pulse treatment(EPT)can significantly improve the microstructure and formability of cold-rolled Cu-bearing stainless steel.The microstructure after EPT was characterized by scanning electron microscopy,transmission electron microscopy,and in-situ tensile testing.It is found that compared with conventional heat treatment,EPT process can significantly promote the nucleation rate and mobility at grain boundaries of the deformed samples,greatly accelerating the recovery and static recrystallization of Cu-bearing stainless steel samples at lower temperatures and contributing to the recovery of anisotropy and the re-molding of deformed samples.Microstructural characterization and theoretical analyses show that the rapid recrystallization during EPT process is caused not only by Joule heating effects but also by non-thermal effects that accelerate grain boundary migration and dislocation destruction and regeneration.In addition,EPT process significantly accelerated the nucleation and precipitation growth of Cu-rich phase.The coarsening of Cu-rich phase during EPT process is due to not only the high vacancy diffusion coefficient under the action of the electric pulse but also the increase in the vacancy diffusion flux induced by the electromigration in the process of the electric pulse.
基金supported by the National Natural Science Foundations of China(No.52470113 and 52225003,52300125)the 55Engineering Research&Innovation Team Project of Beijing Forestry University(No.BLRC2023B04)Fundamental Research Funds for the Central Universities(QNTD202506)。
文摘As atmospheric CO_(2) concentration continues to rise,carbon capture and utilization(CCU)technology has emerged as a critical strategy toward achieving carbon neutrality.CCU offers a dual advantage of mitigating CO_(2) emissions while producing value-added chemicals and fuels.However,conventional CCU strategies typically decouple the CO_(2) capture and electrochemical conversion processes,resulting in increased system complexity,higher energy demands,and limited economic viability.Building an integrated system of CO_(2) capture and in-situ electroreduction can bridge the technological gap,reduce costs,and ultimately enhance carbon cycle efficiency.In this review,we highlight recent advances in CO_(2) capture and in-situ electroreduction technologies.We first evaluate the strengths and limitations of conventional CCU technologies and the emerging CO_(2) capture and direct utilization technologies.Subsequently,we summarize the breakthroughs in multifunctional catalyst systems and key catalyst optimization strategies,and analyze the mechanisms behind the performance improvement.Meanwhile,we also discuss the application progress of in-situ techniques and theoretical calculations in CO_(2) capture and in-situ electroreduction.Finally,we outline the unresolved scientific and engineering challenges and propose future research directions to accelerate the development of CO_(2) capture and in-situ electroreduction.
基金Supported by the National Natural Science Foundation of China Enterprise Innovation and Development Joint Fund Project(U22B6004)National Natural Science Foundation of China and Youth Science Fund Project(4250021468)CNPC Changqing Oilfield Company Key Core Technology Research Project(KJZX2023-01)。
文摘In-situ heating conversion is the most practical recovery method for lacustrine low-to-medium maturity shale oil.However,the energy output-input ratio must exceed the economic threshold to achieve commercial development.This paper systematically investigates the mechanism of super-rich accumulation of organic matter in continental shale,sweet spot evaluation,optimal heating windows,and appropriate well types and patterns from the perspectives of enhancing energy output and reducing energy input.(1)The super-rich accumulation of organic matter in lacustrine shale is primarily controlled by the intensity,frequency,and preservation of external material inputs,and is related to moderate volcanic and hydrothermal activities,marine transgressions,with total organic carbon content greater than or equal to 6%.(2)The quality of organic-rich intervals is related to the type of source material and hydrocarbon generation potential.The in-situ conversion-derived hydrocarbon quality index(HQI)is established,and the zones exhibiting HQI>450 are defined as sweet spots.(3)Considering the characteristics of the organic matter conversion material field and seepage field,the temperature interval 300-370℃is recommended as the optimal heating window for the Chang 7_(3)sub-member of the Triassic Yanchang Formation in the Ordos Basin.Based on the advantages of thermal conductivity,permeability,and hydrocarbon expulsion efficiency along the bedding direction during in-situ heating,the“horizontal well heating+vertical well development”scheme is proposed,which has demonstrated significant enhancement in both recovery factor and energy output-input ratio,making it the optimal in-situ conversion process.The research findings provide a theoretical and technical foundation for the economical and efficient development of low-to-medium maturity shale oil.
