Lithium-sulfur(Li-S)batteries have great promise for next-generation energy storage devices due to the high theoretical specific capacity(1675 mAh g^(-1))of sulfur with chemical conversion for charge storage.However,t...Lithium-sulfur(Li-S)batteries have great promise for next-generation energy storage devices due to the high theoretical specific capacity(1675 mAh g^(-1))of sulfur with chemical conversion for charge storage.However,their practical use is hindered by the slow redox kinetics of sulfur and the“shuttle effect”arising from dissolved lithium polysulfides(LiPSs).In recent years,various carbon-based materials have served as sulfur hosts and catalysts for accelerating sulfur conversion redox kinetics and alleviating LiPS shuttling.However,they often suffer from irreversible passivation and structural changes that destroy their long-term performance.We consider the main problems limiting their stability,including excessive LiPS adsorption,passivation by insulating Li2S,and surface reconstruction,and clarify how these factors lead to capacity fade.We then outline effective strategies for achieving long-term sulfur catalysis,focusing on functional carbon,such as designing suitable carbon-supported catalyst interfaces,creating well-distributed active sites,adding cocatalysts to improve electron transfer,and using carbon-based protective layers to suppress unwanted side reactions.Using this information should enable the development of stable,high-activity catalysts capable of long-term operation under practical conditions in Li-S batteries.展开更多
An iron-containing SBA-15（Fe-SBA-15） has been synthesized via one-pot hydrothermal method under weak acidic conditions. A series of characterizations show nanocomposite materials of iron particles supported over mes...An iron-containing SBA-15（Fe-SBA-15） has been synthesized via one-pot hydrothermal method under weak acidic conditions. A series of characterizations show nanocomposite materials of iron particles supported over mesostructured materials. The catalytic activity of these iron-containing SBA-15 materials has been tested for the heterogeneous Fenton degradation of phenolic aqueous solutions. The catalytic performance has beta monitored in terms of phenol conversion, whereas the catalytic stability was evaluated by catalyst recycle. The influence of concentration of hydrogen peroxide, catalyst loading, catalyst prepared with different Fe/Si molar ratios in the gel and pH values of the solution on phenol conversion has been studied. Achieving a good catalytic performance accompanied with a noteworthy stability, Fe-SBA-15 materials prepared by this method are shown as the successful catalyst for degradation of phenolic aqueous solutions by Fenton process.展开更多
HZSM-5, Al_2O_3, TiO_2 and SiO_2 supported CeO_2-ZrO_2-CrO_x catalysts were prepared by deposition-precipitation method and tested for deep catalytic oxidation of 1,2-dichloroethane（DCE）, as one of the common chlori...HZSM-5, Al_2O_3, TiO_2 and SiO_2 supported CeO_2-ZrO_2-CrO_x catalysts were prepared by deposition-precipitation method and tested for deep catalytic oxidation of 1,2-dichloroethane（DCE）, as one of the common chlorinated organic pollutants. All the catalysts were characterized by means of N_2 adsorption-desorption, X-ray photoelectron spectroscopy（XPS）, ammonia-temperatureprogrammed desorption（NH_3-TPD） and hydrogen temperature-programmed reduction（H2-TPR）. The characterization results revealed that there was strongly synergistic effect between the oxidizability of CZCr species and the acidity of supports, which obviously promoted the catalytic activity for DCE degradation. 20% CZCr/HZSM-5 showed the highest activity and good durability during the long-term continuous test. The catalytic activity decreased in the order： 20%CZCr/HZSM-5〉CZCr〉20%CZCr/TiO_2〉20%CZCr/Al_2O_3〉20%CZCr/SiO_2.展开更多
Co-precipitation method was selected for the preparation of Ni/Al_2O_3, Ni/ZrO_2 and Ni/CeO_2 catalysts, and their performances in methanation were investigated in this study. The structure and surface properties of t...Co-precipitation method was selected for the preparation of Ni/Al_2O_3, Ni/ZrO_2 and Ni/CeO_2 catalysts, and their performances in methanation were investigated in this study. The structure and surface properties of these catalysts were characterized by BET, XRD, H_2-TPD, TEM and H_2-TPR. The results showed that the catalytic activity at low temperature followed the order: Ni/Al_2O_3>Ni/ZrO_2>Ni/CeO_2. Ni/Al_2O_3 catalyst presented the best catalytic performance with the highest CH_4 selectivity of 94.5%. The characterization results indicated that the dispersion of the active component Ni was the main factor affecting the catalytic activity and the one with higher dispersion gave better performance.展开更多
The oxygen evolution reaction(OER)is a key process in water splitting for hydrogen production,yet its sluggish kinetics pose significant challenges for catalyst development.In this work,we present the first systematic...The oxygen evolution reaction(OER)is a key process in water splitting for hydrogen production,yet its sluggish kinetics pose significant challenges for catalyst development.In this work,we present the first systematic study on isostructural 2D coordination polymers(CPs)based on 1,10-ferrocenediyl-bis(H-phosphinic)acid,with cobalt,manganese,and cadmium metals as electrocatalysts for OER.These polymers were synthesized via a facile solution reaction,yielding crystalline materials with excellent structural integrity.The electrocatalytic performance of CPs composites,prepared with carbon and phosphonium ionic liquid,was evaluated in 0.1 M KOH using a three-electrode system.Notably,the Co-and Cd-based CPs demonstrated exceptional OER activity,achieving an overpotential as low as 236–255 mV at 10 mA cm^(-2),surpassing those of many previously reported CP-based OER catalysts.Furthermore,these materials exhibited high stability over prolonged electrolysis,maintaining their activity without significant degradation.This work not only introduces a new class of ferrocenyl phosphinatebased CPs as highly active and durable OER catalysts but also provides valuable insights into their structureactivity relationships,paving the way for future advancements in electrocatalysis.展开更多
Intermetallic Pt-based nanoparticles have displayed excellent activity for the oxygen reduction reaction(ORR)in fuel cells.However,it remains a great challenge to synthesize highly atomically ordered Pt-based nanopart...Intermetallic Pt-based nanoparticles have displayed excellent activity for the oxygen reduction reaction(ORR)in fuel cells.However,it remains a great challenge to synthesize highly atomically ordered Pt-based nanoparticle catalysts because the formation of an atomically ordered structure usually requires high-temperature annealing accompanied by grain sintering.Here we report the direct epitaxial growth of well-aligned,highly atomically ordered Pt3 Fe and PtFe nanoparticles(<5 nm)on single-walled carbon nanotube(SWCNT)bundles films.The long-range periodically symmetric van der Waals(vdW)interac-tions between SWCNT bundles and Pt-Fe nanoparticles play an important role in promoting not only the alignment ordering of inter-nanoparticles but also the atomic ordering of intra-nanoparticles.The ordered Pt_(3)Fe/SWCNT catalyst showed enhanced ORR catalytic performance of 2.3-fold higher mass activity and 3.1-fold higher specific activity than commercial Pt/C.Moreover,the formation of an interlocked inter-face and strong vdW interaction endow the Pt-Fe/SWCNT catalysts with extreme long-term stability in potential cycling and excellent anti-thermal sintering ability.展开更多
After publication of the research article "Constructing inter diffusive PtCuNi/WOg interface to enhance the catalytic activity and stability in oxygen reduction"(https://doi.org/10.1007/s42864-023-00226-0).T...After publication of the research article "Constructing inter diffusive PtCuNi/WOg interface to enhance the catalytic activity and stability in oxygen reduction"(https://doi.org/10.1007/s42864-023-00226-0).The authors discovered that the"Acknowledgement"is missing from the published online version,due to the unintentional mistake when preparing the manuscript.This could be unfair to the entities/scholars providing meaningful help to this work,as well as the funding agency that provided the financial support to this work.Therefore,an erratum is requested by the authors to acknowledge the following parties.展开更多
Gold stabilized on reducible oxide （CeO2 and FeOx） and irreducible oxide （γ‐Al2O3, SiO2, and HZSM‐5） were prepared by deposition precipitation method and tested for catalytic oxidation of formaldehyde （HCHO） ...Gold stabilized on reducible oxide （CeO2 and FeOx） and irreducible oxide （γ‐Al2O3, SiO2, and HZSM‐5） were prepared by deposition precipitation method and tested for catalytic oxidation of formaldehyde （HCHO） at room temperature under high GHSV of 600000 ml/（g＆#183;s）. Au/γ‐Al2O3 cata‐lyst showed distinctive catalytic performance, presenting the highest initial HCHO conversion and stability. Correlating the reaction rate with Au particle size, there is a linear relationship, suggesting that the smaller Au particle size with higher dispersion possesses high reactivity for HCHO oxida‐tion. All the catalysts deactivated at high GHSV （600000 ml/（g＆#183;s））, but in a quite different rate. Re‐ducible oxide （CeO2 and FeOx） could stabilize gold through O linkage and therefore exhibits a better stability for HCHO oxidation reaction. However, the aggregation of gold particles occurred over Au/SiO2 and Au/HZSM‐5 catalysts, which result in the fast deactivation. Therefore, our results sug‐gest that the reducibility of the supports for Au catalysis has no direct influence on the activity, but affects the catalytic stability.展开更多
CO_(2)hydrogenation has been considered to be a highly promising route for the production of high-value olefins(HVOs)while also mitigating CO_(2)emissions.However,it is challenging to achieve high selectivity and main...CO_(2)hydrogenation has been considered to be a highly promising route for the production of high-value olefins(HVOs)while also mitigating CO_(2)emissions.However,it is challenging to achieve high selectivity and maintain stable performance for HVOs(ethylene,propylene,and linear a-olefins)over a prolonged reaction time due to the difficulty in precise control of carbon coupling and rapid catalyst deactivation.Herein,we present a selective Ba and Na co-modified Fe catalyst enriched with Fe_(5)C_(2)and Fe_(3)C active sites that can boost HVO synthesis with up to 66.1%selectivity at an average CO_(2)conversion of 38%for over 500 h.Compared to traditional NaFe catalyst,the combined effect of Ba and Na additives in the NaBaFe-0.5 catalyst suppressed excess oxidation of FeCxsites by H_(2)O.The absence of Fe3O4phase in the spent NaBaFe-0.5 catalyst reflects the stabilization effect of the co-modifiers on the FeCxsites.This study provides a strategy to design Fe-based catalysts that can be scaled up for the stable synthesis of HVOs from CO_(2)hydrogenation.展开更多
Methane partial oxidation to methanol （MPOM） using dielectric barrier discharge over a Fe2O3-CuO/γ-Al2O3 catalyst was performed.The multicomponent catalyst was combined with plasma in two different configurations,i...Methane partial oxidation to methanol （MPOM） using dielectric barrier discharge over a Fe2O3-CuO/γ-Al2O3 catalyst was performed.The multicomponent catalyst was combined with plasma in two different configurations,i.e.,in-plasma catalysis （IPC） and post-plasma catalysis （PPC）.It was found that the catalytic performance of the catalysts for MPOM was strongly dependent on the hybrid configuration.A better synergistic performance of plasma and catalysis was achieved in the IPC configuration,but the catalysts packed in the discharge zone showed lower stability than those connected to the discharge zone in sequence.Active species,such as ozone,atomic oxygen and methyl radicals,were produced from the plasma-catalysis process,and made a major contribution to methanol synthesis.These active species were identified by the means of in situ optical emission spectra,ozone measurement and FT-IR spectra.It was confirmed that the amount of active species in the IPC system was greater than that in the PPC system.The results of TG,XRD,and N2 adsorption-desorption revealed that carbon deposition on the spent catalyst surface was responsible for the catalyst deactivation in the IPC configuration.展开更多
Herein, lanthanum was incorporated via hydrothermal synthesis into a MCM-41 framework structure with La/Si molar ratios from 0.01 to 0.1. Samples of NiO supported on LaMCM-41 were prepared using the impregnation metho...Herein, lanthanum was incorporated via hydrothermal synthesis into a MCM-41 framework structure with La/Si molar ratios from 0.01 to 0.1. Samples of NiO supported on LaMCM-41 were prepared using the impregnation method. The catalyst performance was evaluated using a fixed bed CO methanation reactor. A Ni/LaMCM-41 catalyst with La/Si = 0.1 shows the best catalytic performance with a CO conversion of almost 100% and a CH4 selectivity of 89.5% at 250 ℃ under a pressure of 1.5 MPa and at an airspeed of 36,000 mL/（g·h）. Compared with Ni-La/MCM-41（La/Si = 0.1） and Ni/MCM-41 prepared via the impregnation method, Ni/LaMCM-41（La/Si = 0.1） shows a higher CO conversion and CH4 selectivity.In a 100 h stability test, the Ni/LaMCM-41（La/Si = 0.1） catalyst shows excellent stability; furthermore, the CO conversion is always greater than 98.0%, which is significantly better than the results for Ni/MCM-41.We experimentally demonstrate that elemental La enters the framework of MCM-41. The Ni/LaMCM-41 catalyst performs well because the La reduces the average particle size of the NiO particles and enhances the interaction between NiO and MCM-41; moreover, the introduction of La significantly inhibits the sintering of the catalyst and the formation of carbon deposits.展开更多
Porous Pt thin films were prepared on carbon papers by a single-step ultra-high dc magnetron sputtering method to obtain ideal electrodes for proton exchange membrane fuel cells.The platinum loading of the electrocata...Porous Pt thin films were prepared on carbon papers by a single-step ultra-high dc magnetron sputtering method to obtain ideal electrodes for proton exchange membrane fuel cells.The platinum loading of the electrocatalyst layer is controlled at about 0.1 mg·cm^(-2).Structural characteristics and catalytic activities of the films were analyzed by scanning electron microscopy,atomic force microscopy,X-ray diffraction,cyclic voltammetry,and stress durability testing methods.The effect of treatment conditions of a substrate on the structural and performance characteristics of the catalytic films was shown as well.Films produced on acid-treated carbon papers at the argon pressure of 0.01 mbar possessed a homogeneous,highly developed surface along with a porous structure.Compared to Pt/TCPW(Toray carbon papers soaked in ultrapure water)electrodes,the film obtained on the acid-treated substrate had a larger electrochemical surface area(163.33 m^(2)·g^(-1))and exhibited better catalytic stability and durability due to a porous structure as a result of Pt particle accumulation.展开更多
Catalytic hydrogenation is an appropriate method for the improvement of C9 petroleum resin（C9PR） quality. In this study, the Ni2P/SiO2（containing 10% of Ni） catalyst prepared by the temperature-programmed reductio...Catalytic hydrogenation is an appropriate method for the improvement of C9 petroleum resin（C9PR） quality. In this study, the Ni2P/SiO2（containing 10% of Ni） catalyst prepared by the temperature-programmed reduction（TPR） method was used for hydrogenation of C9 petroleum resins. The effect of reaction conditions on catalytic performance was studied, and the results showed that the optimum reaction temperature, pressure and liquid hourly space velocity（LHSV） was 250 ℃, 6.0 MPa, and 1.0 h-1, respectively. The bromine numbers of hydrogenated products were maintained at low values（250 mg Br/100g） within 300h, showing the high activity and stability of Ni2P/SiO2 catalyst. The fresh and spent catalysts were characterized by X-ray diffraction（XRD）, BET surface area（BET） analysis, scanning electron microscopy（SEM）, transmission electron microscopy（TEM）, Fourier transform infrared（FTIR） pyridine adsorption, and X-ray photoelectron spectroscopy（XPS）. Compared with the traditional sulfurated-Ni W catalysts, Ni2P possessed globe-like structure instead of layered structure like the active phase of Ni WS, thereof exposing more active sites, which were responsible for the high activity of Ni2P/SiO2 catalyst. The stability of Ni2P/SiO2 catalyst was probably attributed to its high sulfur tolerance, antisintering, anti-coking and carbon-resistance ability. These properties might be further ascribed to the special Ni-P-S surface phase, high thermal stability of Ni2P nanoparticles and weak surface acidity for the Ni2P/SiO2 catalyst.展开更多
The present work establishes a systematic approach based on the application of in-situ Fourier transform infrared spectroscopy （FTIR） for the investigation of the crystal structure, thermal stability, redox behavior...The present work establishes a systematic approach based on the application of in-situ Fourier transform infrared spectroscopy （FTIR） for the investigation of the crystal structure, thermal stability, redox behavior （temperature-programmed reduction/temperatureprogrammed re-oxidation） as well as the catalytic properties of Co3O4 thin films. The syntheses of Co3O4 were achieved by chemical vapor deposition in the temperature range of 400-500℃. The structure analysis of the as-prepared material revealed the presence of two prominent IR bands peaking at 544 cm-1 （υ1） and 650 cm-1 （υ2） respectively, which originate from the stretching vibrations of the Co-O bond, characteristic of the Co3O4 spinel. The lattice stability limit of Co3O4 was estimated to be above 650℃. The redox properties of the spinel structure were determined by integrating the area under the emission bands υ1 and υ2 as a function of the temperature. Moreover, Co3O4 has been successfully tested as a catalyst towards complete oxidation of dimethyl ether below 340 ℃. The exhaust gas analysis during the catalytic process by in situ absorption FTIR revealed that only CO2 and H2O were detected as the final products in the catalytic reaction. The redox behavior suggests that the oxidation of dimethyl ether over Co3O4 follows a Mars-van Krevelen type mechanism. The comprehensive application of in situ FTIR provides a novel diagnostic tool in characterization and performance test of catalysts.展开更多
The catalytic activity of polycobaltprotoporphyrin(PCoPP)was compared with adsorbed cobaltprotoporphyrin monolayer.The results have shown that PCoPP film shows higher catalytic activity and stability than monolayer on...The catalytic activity of polycobaltprotoporphyrin(PCoPP)was compared with adsorbed cobaltprotoporphyrin monolayer.The results have shown that PCoPP film shows higher catalytic activity and stability than monolayer on glass carbon electrode in both alkaline and acid solution. Catalytic activity of PCoPP goes through a maximum with increase of film thickness.A model was proposed to explain such dependence.The effect of film thickness and solution pH on the stability of PCoPP film was studied.展开更多
Silicoaluminophosphates （SAPOs） with different pore structures were synthesized through the implementation of polyethylene glycol （PEG） as a mesopores impregnation agent. Using PEGs with different molecular weigh...Silicoaluminophosphates （SAPOs） with different pore structures were synthesized through the implementation of polyethylene glycol （PEG） as a mesopores impregnation agent. Using PEGs with different molecular weights （MWs） and concentrations in the synthesis precursor, several samples were synthesized and characterized. Applying a PEG capping agent to the precursors led to the formation of tuned mesopores within the microporous matrix of the SAPO. The effects of the PEG molecular weight and PEG/Al molar ratio were investigated to maximize the efficiency of the catalyst in the methanol-to-olefin （MTO） process. Using PEG with a MW of 6000 resulted in the formation of both Zeolite Rho and chabazite structural frameworks （i.e., DNL-6 and SAPO-34）. Pure SAPO-34 samples were successfully prepared using PEG with a MW of 4000. Our results showed that the PEG concentrations affect the porosity and acidity of the synthesized materials. Furthermore, the SAPO-34 sample synthesized with PEG （MW of 4000） and a PEG/Al molar ratio of 0.0125 showed a superior catalytic stability in the MTO reaction owing to the tuned bi-modal porosity and tailored acidity pattern. Finally, through reactivation experiments, it was found that the catalyst is stable even after several regeneration cycles.展开更多
Confining active nanoparticles within specific nanoscale spaces is a promising strategy to improve the catalytic activity,selectivity and stability of catalysts.In this study,we present a lattice-matching approach to ...Confining active nanoparticles within specific nanoscale spaces is a promising strategy to improve the catalytic activity,selectivity and stability of catalysts.In this study,we present a lattice-matching approach to confine Co particles within ZnO layers(ZnO/Co/ZnO)for CO_(2) hydrogenation,a critical and challenging reaction in the field of CO_(2) utilization and energy production.XRD patterns reveal that the lattice mismatch between ZnO and hexagonal wurtzite CoO(w-CoO)is only 0.18%,facilitating the epitaxial growth of w-CoO on the ZnO surface,or vice versa.This minimal mismatch enables the successful confinement of w-CoO within the ZnO interlayers.This advanced methodology can also be adapted to diverse ZnO morphologies,allowing the optimization of the confined catalyst mol_(CO_(2))·g_(Co)^(-1)·s^(-1) microstructure.Significantly,when Co particles are confined within the interlayer of ZnO,they exhibit excellent catalytic activity,achieving a rate of 15.8μ for CO_(2) hydrogenation reaction.Moreover,no appreciable deactivation was observed even after 700 h of continuous operation.These results introduce a novel approach for the development of confined catalysts with enhanced activity and long-term stability.展开更多
The Pt Sn/Al_(2)O_(3)catalyst is commonly used in commercial propane dehydrogenation(PDH)processes,but it faces challenges in the deactivation and periodic regeneration due to metal aggregation and coke deposition at ...The Pt Sn/Al_(2)O_(3)catalyst is commonly used in commercial propane dehydrogenation(PDH)processes,but it faces challenges in the deactivation and periodic regeneration due to metal aggregation and coke deposition at high temperatures.Although Al_(penta)^(3+)has been proven to be beneficial for enhancing catalytic stability,bottom-up synthesis protocols usually restrict their applications.Here,a facile post-treatment approach using acetic acid was applied to create color centers(electrons trapped within oxygen vacancies)onγ-Al_(2)O_(3).Notably,the content of Al_(penta)^(3+)was enriched to 18.3%.Then,the pre-established Pt Sn clusters were loaded.The electrons facilitated the formation of ultrafine Pt Sn nanoparticles(~2 nm),and the Al_(penta)^(3+)sites prevented the sintering of Pt Sn by constructing the strong Al_(penta)^(3+)–O–Sn bonds.Furthermore,the catalytic durability of the catalyst prepared by conventional impregnation methods was remarkably extended from 186 h for the color center-free sample to 1,000 h using the HAc–Al_(2)O_(3)support.This facile post-modification was further successfully extended to commercial Al_(2)O_(3)pellets without altering their mechanical properties,highlighting its potential in industrial applications.展开更多
Surface modification of metallic nanocatalysts with organic ligands has emerged as an effective strategy to enhance catalytic selectivity,although offten at the expense of catalytic activity.In this study,we demonstra...Surface modification of metallic nanocatalysts with organic ligands has emerged as an effective strategy to enhance catalytic selectivity,although offten at the expense of catalytic activity.In this study,we demonstrate a compelling approach by surface modifying Pd2S nanocrystals with PPhz ligands,resulting in a catalyst with excellent catalytic activity and durable selectivity for the semi-hydrogenation of terminal alkynes.Experimental and theoretical investigations reveal that the presence of S sites on the Pd surface directs PPh_(3) ligands to preferentially form covalent bonds with S,creating distinctive surface S=PPh_(3) motifs.This configuration induces a partial positive charge on Pd,facilitating hydrogen transfer and thus promoting catalytic activity.Furthermore,the covalent bond between the ligand and catalyst surface forms a robust network,ensuring ligand stability and increasing the hydrogenation energy barrier of olefins.Consequently,the Pd_(4)S@PPhz catalyst exhibits an improved catalytic selectivity with durability in terminal alkyne semi-hydrogenation.This study introduces an effective strategy for designing selective hydrogenation catalysts with an enhanced performance.展开更多
A new class of rhodium complexes with high catalytic activity as well as excellent stability, which was used as catalyst for carbonylation of methanol to acetic acid, is reported. It contains free donor (namely un-coo...A new class of rhodium complexes with high catalytic activity as well as excellent stability, which was used as catalyst for carbonylation of methanol to acetic acid, is reported. It contains free donor (namely un-coordinated donor) atoms which enable to improve its stability by intramolecular substitution reaction. Its synthesis, characteristic and catalytic reaction were discussed here.展开更多
文摘Lithium-sulfur(Li-S)batteries have great promise for next-generation energy storage devices due to the high theoretical specific capacity(1675 mAh g^(-1))of sulfur with chemical conversion for charge storage.However,their practical use is hindered by the slow redox kinetics of sulfur and the“shuttle effect”arising from dissolved lithium polysulfides(LiPSs).In recent years,various carbon-based materials have served as sulfur hosts and catalysts for accelerating sulfur conversion redox kinetics and alleviating LiPS shuttling.However,they often suffer from irreversible passivation and structural changes that destroy their long-term performance.We consider the main problems limiting their stability,including excessive LiPS adsorption,passivation by insulating Li2S,and surface reconstruction,and clarify how these factors lead to capacity fade.We then outline effective strategies for achieving long-term sulfur catalysis,focusing on functional carbon,such as designing suitable carbon-supported catalyst interfaces,creating well-distributed active sites,adding cocatalysts to improve electron transfer,and using carbon-based protective layers to suppress unwanted side reactions.Using this information should enable the development of stable,high-activity catalysts capable of long-term operation under practical conditions in Li-S batteries.
基金the National Natural Science Foundation of China(2040101550574082)
文摘An iron-containing SBA-15（Fe-SBA-15） has been synthesized via one-pot hydrothermal method under weak acidic conditions. A series of characterizations show nanocomposite materials of iron particles supported over mesostructured materials. The catalytic activity of these iron-containing SBA-15 materials has been tested for the heterogeneous Fenton degradation of phenolic aqueous solutions. The catalytic performance has beta monitored in terms of phenol conversion, whereas the catalytic stability was evaluated by catalyst recycle. The influence of concentration of hydrogen peroxide, catalyst loading, catalyst prepared with different Fe/Si molar ratios in the gel and pH values of the solution on phenol conversion has been studied. Achieving a good catalytic performance accompanied with a noteworthy stability, Fe-SBA-15 materials prepared by this method are shown as the successful catalyst for degradation of phenolic aqueous solutions by Fenton process.
基金Project supports from National Nature Science Foundation of China(21177110)
文摘HZSM-5, Al_2O_3, TiO_2 and SiO_2 supported CeO_2-ZrO_2-CrO_x catalysts were prepared by deposition-precipitation method and tested for deep catalytic oxidation of 1,2-dichloroethane（DCE）, as one of the common chlorinated organic pollutants. All the catalysts were characterized by means of N_2 adsorption-desorption, X-ray photoelectron spectroscopy（XPS）, ammonia-temperatureprogrammed desorption（NH_3-TPD） and hydrogen temperature-programmed reduction（H2-TPR）. The characterization results revealed that there was strongly synergistic effect between the oxidizability of CZCr species and the acidity of supports, which obviously promoted the catalytic activity for DCE degradation. 20% CZCr/HZSM-5 showed the highest activity and good durability during the long-term continuous test. The catalytic activity decreased in the order： 20%CZCr/HZSM-5〉CZCr〉20%CZCr/TiO_2〉20%CZCr/Al_2O_3〉20%CZCr/SiO_2.
基金financial support from the National Science and Technology Supporting Plan through contract (2015BAD15B06)the National Natural Science Foundation of China (51661145011)
文摘Co-precipitation method was selected for the preparation of Ni/Al_2O_3, Ni/ZrO_2 and Ni/CeO_2 catalysts, and their performances in methanation were investigated in this study. The structure and surface properties of these catalysts were characterized by BET, XRD, H_2-TPD, TEM and H_2-TPR. The results showed that the catalytic activity at low temperature followed the order: Ni/Al_2O_3>Ni/ZrO_2>Ni/CeO_2. Ni/Al_2O_3 catalyst presented the best catalytic performance with the highest CH_4 selectivity of 94.5%. The characterization results indicated that the dispersion of the active component Ni was the main factor affecting the catalytic activity and the one with higher dispersion gave better performance.
文摘The oxygen evolution reaction(OER)is a key process in water splitting for hydrogen production,yet its sluggish kinetics pose significant challenges for catalyst development.In this work,we present the first systematic study on isostructural 2D coordination polymers(CPs)based on 1,10-ferrocenediyl-bis(H-phosphinic)acid,with cobalt,manganese,and cadmium metals as electrocatalysts for OER.These polymers were synthesized via a facile solution reaction,yielding crystalline materials with excellent structural integrity.The electrocatalytic performance of CPs composites,prepared with carbon and phosphonium ionic liquid,was evaluated in 0.1 M KOH using a three-electrode system.Notably,the Co-and Cd-based CPs demonstrated exceptional OER activity,achieving an overpotential as low as 236–255 mV at 10 mA cm^(-2),surpassing those of many previously reported CP-based OER catalysts.Furthermore,these materials exhibited high stability over prolonged electrolysis,maintaining their activity without significant degradation.This work not only introduces a new class of ferrocenyl phosphinatebased CPs as highly active and durable OER catalysts but also provides valuable insights into their structureactivity relationships,paving the way for future advancements in electrocatalysis.
基金supported by the National Natural Science Foundation of China(grant Nos.52073290 and 51927803)the Liaoning Province Science and Technology Plan Project(No.2022-MS-011)the Shenyang science and technology plan project(23-407-3-23).
文摘Intermetallic Pt-based nanoparticles have displayed excellent activity for the oxygen reduction reaction(ORR)in fuel cells.However,it remains a great challenge to synthesize highly atomically ordered Pt-based nanoparticle catalysts because the formation of an atomically ordered structure usually requires high-temperature annealing accompanied by grain sintering.Here we report the direct epitaxial growth of well-aligned,highly atomically ordered Pt3 Fe and PtFe nanoparticles(<5 nm)on single-walled carbon nanotube(SWCNT)bundles films.The long-range periodically symmetric van der Waals(vdW)interac-tions between SWCNT bundles and Pt-Fe nanoparticles play an important role in promoting not only the alignment ordering of inter-nanoparticles but also the atomic ordering of intra-nanoparticles.The ordered Pt_(3)Fe/SWCNT catalyst showed enhanced ORR catalytic performance of 2.3-fold higher mass activity and 3.1-fold higher specific activity than commercial Pt/C.Moreover,the formation of an interlocked inter-face and strong vdW interaction endow the Pt-Fe/SWCNT catalysts with extreme long-term stability in potential cycling and excellent anti-thermal sintering ability.
文摘After publication of the research article "Constructing inter diffusive PtCuNi/WOg interface to enhance the catalytic activity and stability in oxygen reduction"(https://doi.org/10.1007/s42864-023-00226-0).The authors discovered that the"Acknowledgement"is missing from the published online version,due to the unintentional mistake when preparing the manuscript.This could be unfair to the entities/scholars providing meaningful help to this work,as well as the funding agency that provided the financial support to this work.Therefore,an erratum is requested by the authors to acknowledge the following parties.
基金supported by the National Natural Science Foundation of China(21373037,21577013)China Postdoctoral Science Foundation(2014M560201)the Fundamental Research Funds for the Central Universities(DUT15TD49,DUT16ZD224)~~
文摘Gold stabilized on reducible oxide （CeO2 and FeOx） and irreducible oxide （γ‐Al2O3, SiO2, and HZSM‐5） were prepared by deposition precipitation method and tested for catalytic oxidation of formaldehyde （HCHO） at room temperature under high GHSV of 600000 ml/（g＆#183;s）. Au/γ‐Al2O3 cata‐lyst showed distinctive catalytic performance, presenting the highest initial HCHO conversion and stability. Correlating the reaction rate with Au particle size, there is a linear relationship, suggesting that the smaller Au particle size with higher dispersion possesses high reactivity for HCHO oxida‐tion. All the catalysts deactivated at high GHSV （600000 ml/（g＆#183;s））, but in a quite different rate. Re‐ducible oxide （CeO2 and FeOx） could stabilize gold through O linkage and therefore exhibits a better stability for HCHO oxidation reaction. However, the aggregation of gold particles occurred over Au/SiO2 and Au/HZSM‐5 catalysts, which result in the fast deactivation. Therefore, our results sug‐gest that the reducibility of the supports for Au catalysis has no direct influence on the activity, but affects the catalytic stability.
基金supported by the National Natural Science Foundation of China(21802138,21773234 and 22078315)the‘‘Transformational Technologies for Clean Energy and Demonstration’’,Strategic Priority Research Program of the Chinese Academy of Sciences(XDA 21090203)+3 种基金the Youth Innovation Promotion Association of Chinese Academy of Sciences(2020189)the Natural Science Foundation of Liaoning Province(2022-MS-027)the Youth Science and Technology Star Project Support Program of Dalian City(2021RQ123),DICP(Grant:DICP I202138)the University of Chinese Academy of Sciences(UCAS)for UCAS Scholarship。
文摘CO_(2)hydrogenation has been considered to be a highly promising route for the production of high-value olefins(HVOs)while also mitigating CO_(2)emissions.However,it is challenging to achieve high selectivity and maintain stable performance for HVOs(ethylene,propylene,and linear a-olefins)over a prolonged reaction time due to the difficulty in precise control of carbon coupling and rapid catalyst deactivation.Herein,we present a selective Ba and Na co-modified Fe catalyst enriched with Fe_(5)C_(2)and Fe_(3)C active sites that can boost HVO synthesis with up to 66.1%selectivity at an average CO_(2)conversion of 38%for over 500 h.Compared to traditional NaFe catalyst,the combined effect of Ba and Na additives in the NaBaFe-0.5 catalyst suppressed excess oxidation of FeCxsites by H_(2)O.The absence of Fe3O4phase in the spent NaBaFe-0.5 catalyst reflects the stabilization effect of the co-modifiers on the FeCxsites.This study provides a strategy to design Fe-based catalysts that can be scaled up for the stable synthesis of HVOs from CO_(2)hydrogenation.
基金supported by the National Natural Science Foundation of China(No. 20836008 and U0633003)the Zhejiang Provincial Natural Science Foundation of China(No. Y5080192)+3 种基金the Project of Science and Technology Department of Zhejiang Province of China(2007C13061)MOST Project of China(No. 2007AA06Z339,No. 2008BAC32B06 and No. 2007AA06A409)the Open Project Program of Key Laboratory of Non-point Sources Pollution Controlthe Ministry of Agriculture of the People’s Republic of China and Science Foundation of Chinese University
文摘Methane partial oxidation to methanol （MPOM） using dielectric barrier discharge over a Fe2O3-CuO/γ-Al2O3 catalyst was performed.The multicomponent catalyst was combined with plasma in two different configurations,i.e.,in-plasma catalysis （IPC） and post-plasma catalysis （PPC）.It was found that the catalytic performance of the catalysts for MPOM was strongly dependent on the hybrid configuration.A better synergistic performance of plasma and catalysis was achieved in the IPC configuration,but the catalysts packed in the discharge zone showed lower stability than those connected to the discharge zone in sequence.Active species,such as ozone,atomic oxygen and methyl radicals,were produced from the plasma-catalysis process,and made a major contribution to methanol synthesis.These active species were identified by the means of in situ optical emission spectra,ozone measurement and FT-IR spectra.It was confirmed that the amount of active species in the IPC system was greater than that in the PPC system.The results of TG,XRD,and N2 adsorption-desorption revealed that carbon deposition on the spent catalyst surface was responsible for the catalyst deactivation in the IPC configuration.
基金Project supported by the National Natural Science Foundation of China(U1203293)the Doctor Foundation of Bingtuan(2013BB010)the Foundation of Young Scientist in Shihezi University(2013ZRKXJQ03)
文摘Herein, lanthanum was incorporated via hydrothermal synthesis into a MCM-41 framework structure with La/Si molar ratios from 0.01 to 0.1. Samples of NiO supported on LaMCM-41 were prepared using the impregnation method. The catalyst performance was evaluated using a fixed bed CO methanation reactor. A Ni/LaMCM-41 catalyst with La/Si = 0.1 shows the best catalytic performance with a CO conversion of almost 100% and a CH4 selectivity of 89.5% at 250 ℃ under a pressure of 1.5 MPa and at an airspeed of 36,000 mL/（g·h）. Compared with Ni-La/MCM-41（La/Si = 0.1） and Ni/MCM-41 prepared via the impregnation method, Ni/LaMCM-41（La/Si = 0.1） shows a higher CO conversion and CH4 selectivity.In a 100 h stability test, the Ni/LaMCM-41（La/Si = 0.1） catalyst shows excellent stability; furthermore, the CO conversion is always greater than 98.0%, which is significantly better than the results for Ni/MCM-41.We experimentally demonstrate that elemental La enters the framework of MCM-41. The Ni/LaMCM-41 catalyst performs well because the La reduces the average particle size of the NiO particles and enhances the interaction between NiO and MCM-41; moreover, the introduction of La significantly inhibits the sintering of the catalyst and the formation of carbon deposits.
基金Funded by the Doctoral Fund of Southwest University of Science and Technology(Nos.19zx7131 and 18zx7132)the Applied Fundamental Research Projects of Science and Technology Department of Sichuan Province(No.2020YJ0333)+1 种基金the Science and Technology on Plasma Physics Laboratory:6142A04180405Science and Technology on Plasma Physics Laboratory:ZY2018-07。
文摘Porous Pt thin films were prepared on carbon papers by a single-step ultra-high dc magnetron sputtering method to obtain ideal electrodes for proton exchange membrane fuel cells.The platinum loading of the electrocatalyst layer is controlled at about 0.1 mg·cm^(-2).Structural characteristics and catalytic activities of the films were analyzed by scanning electron microscopy,atomic force microscopy,X-ray diffraction,cyclic voltammetry,and stress durability testing methods.The effect of treatment conditions of a substrate on the structural and performance characteristics of the catalytic films was shown as well.Films produced on acid-treated carbon papers at the argon pressure of 0.01 mbar possessed a homogeneous,highly developed surface along with a porous structure.Compared to Pt/TCPW(Toray carbon papers soaked in ultrapure water)electrodes,the film obtained on the acid-treated substrate had a larger electrochemical surface area(163.33 m^(2)·g^(-1))and exhibited better catalytic stability and durability due to a porous structure as a result of Pt particle accumulation.
基金financially supported by the Scientific Research Fund of Zhejiang Provincial Education Department (Y201225114)the Natural Science Foundation of Zhejiang Province (LY13B030006)
文摘Catalytic hydrogenation is an appropriate method for the improvement of C9 petroleum resin（C9PR） quality. In this study, the Ni2P/SiO2（containing 10% of Ni） catalyst prepared by the temperature-programmed reduction（TPR） method was used for hydrogenation of C9 petroleum resins. The effect of reaction conditions on catalytic performance was studied, and the results showed that the optimum reaction temperature, pressure and liquid hourly space velocity（LHSV） was 250 ℃, 6.0 MPa, and 1.0 h-1, respectively. The bromine numbers of hydrogenated products were maintained at low values（250 mg Br/100g） within 300h, showing the high activity and stability of Ni2P/SiO2 catalyst. The fresh and spent catalysts were characterized by X-ray diffraction（XRD）, BET surface area（BET） analysis, scanning electron microscopy（SEM）, transmission electron microscopy（TEM）, Fourier transform infrared（FTIR） pyridine adsorption, and X-ray photoelectron spectroscopy（XPS）. Compared with the traditional sulfurated-Ni W catalysts, Ni2P possessed globe-like structure instead of layered structure like the active phase of Ni WS, thereof exposing more active sites, which were responsible for the high activity of Ni2P/SiO2 catalyst. The stability of Ni2P/SiO2 catalyst was probably attributed to its high sulfur tolerance, antisintering, anti-coking and carbon-resistance ability. These properties might be further ascribed to the special Ni-P-S surface phase, high thermal stability of Ni2P nanoparticles and weak surface acidity for the Ni2P/SiO2 catalyst.
文摘The present work establishes a systematic approach based on the application of in-situ Fourier transform infrared spectroscopy （FTIR） for the investigation of the crystal structure, thermal stability, redox behavior （temperature-programmed reduction/temperatureprogrammed re-oxidation） as well as the catalytic properties of Co3O4 thin films. The syntheses of Co3O4 were achieved by chemical vapor deposition in the temperature range of 400-500℃. The structure analysis of the as-prepared material revealed the presence of two prominent IR bands peaking at 544 cm-1 （υ1） and 650 cm-1 （υ2） respectively, which originate from the stretching vibrations of the Co-O bond, characteristic of the Co3O4 spinel. The lattice stability limit of Co3O4 was estimated to be above 650℃. The redox properties of the spinel structure were determined by integrating the area under the emission bands υ1 and υ2 as a function of the temperature. Moreover, Co3O4 has been successfully tested as a catalyst towards complete oxidation of dimethyl ether below 340 ℃. The exhaust gas analysis during the catalytic process by in situ absorption FTIR revealed that only CO2 and H2O were detected as the final products in the catalytic reaction. The redox behavior suggests that the oxidation of dimethyl ether over Co3O4 follows a Mars-van Krevelen type mechanism. The comprehensive application of in situ FTIR provides a novel diagnostic tool in characterization and performance test of catalysts.
文摘The catalytic activity of polycobaltprotoporphyrin(PCoPP)was compared with adsorbed cobaltprotoporphyrin monolayer.The results have shown that PCoPP film shows higher catalytic activity and stability than monolayer on glass carbon electrode in both alkaline and acid solution. Catalytic activity of PCoPP goes through a maximum with increase of film thickness.A model was proposed to explain such dependence.The effect of film thickness and solution pH on the stability of PCoPP film was studied.
文摘Silicoaluminophosphates （SAPOs） with different pore structures were synthesized through the implementation of polyethylene glycol （PEG） as a mesopores impregnation agent. Using PEGs with different molecular weights （MWs） and concentrations in the synthesis precursor, several samples were synthesized and characterized. Applying a PEG capping agent to the precursors led to the formation of tuned mesopores within the microporous matrix of the SAPO. The effects of the PEG molecular weight and PEG/Al molar ratio were investigated to maximize the efficiency of the catalyst in the methanol-to-olefin （MTO） process. Using PEG with a MW of 6000 resulted in the formation of both Zeolite Rho and chabazite structural frameworks （i.e., DNL-6 and SAPO-34）. Pure SAPO-34 samples were successfully prepared using PEG with a MW of 4000. Our results showed that the PEG concentrations affect the porosity and acidity of the synthesized materials. Furthermore, the SAPO-34 sample synthesized with PEG （MW of 4000） and a PEG/Al molar ratio of 0.0125 showed a superior catalytic stability in the MTO reaction owing to the tuned bi-modal porosity and tailored acidity pattern. Finally, through reactivation experiments, it was found that the catalyst is stable even after several regeneration cycles.
基金supported by the National Natural Science Foundation of China(Nos.42277485,21976141,and 22102220)the Department of Science and Technology of Hubei Province(No.2021CFA034)+2 种基金the Department of Education of Hubei Province(No.T2020011)the State Key Laboratory of Pulp and Paper Engineering(No.202301)Fundação para a Ciência e Tecnologia and Ministério da Ciência,Tecnologia e Ensino Superior,Portugal(DOIs:10.54499/LA/P/0008/2020,10.54499/UIDP/50006/2020,10.54499/UIDB/50006/2020,and 10.54499/CEECINST/00102/2018/CP1567/CT0026).
文摘Confining active nanoparticles within specific nanoscale spaces is a promising strategy to improve the catalytic activity,selectivity and stability of catalysts.In this study,we present a lattice-matching approach to confine Co particles within ZnO layers(ZnO/Co/ZnO)for CO_(2) hydrogenation,a critical and challenging reaction in the field of CO_(2) utilization and energy production.XRD patterns reveal that the lattice mismatch between ZnO and hexagonal wurtzite CoO(w-CoO)is only 0.18%,facilitating the epitaxial growth of w-CoO on the ZnO surface,or vice versa.This minimal mismatch enables the successful confinement of w-CoO within the ZnO interlayers.This advanced methodology can also be adapted to diverse ZnO morphologies,allowing the optimization of the confined catalyst mol_(CO_(2))·g_(Co)^(-1)·s^(-1) microstructure.Significantly,when Co particles are confined within the interlayer of ZnO,they exhibit excellent catalytic activity,achieving a rate of 15.8μ for CO_(2) hydrogenation reaction.Moreover,no appreciable deactivation was observed even after 700 h of continuous operation.These results introduce a novel approach for the development of confined catalysts with enhanced activity and long-term stability.
基金supported from the National Key R&D Program of China(2022YFA1504500)the National Natural Science Foundation of China(92261207,21890752,and 22202164)for financial support+2 种基金support from the Natural Science Foundation of Fujian Province(2023J05006)the Fujian Provincial Chemistry Discipline Alliancethe Fundamental Research Funds for the Central Universities(20720230002)。
文摘The Pt Sn/Al_(2)O_(3)catalyst is commonly used in commercial propane dehydrogenation(PDH)processes,but it faces challenges in the deactivation and periodic regeneration due to metal aggregation and coke deposition at high temperatures.Although Al_(penta)^(3+)has been proven to be beneficial for enhancing catalytic stability,bottom-up synthesis protocols usually restrict their applications.Here,a facile post-treatment approach using acetic acid was applied to create color centers(electrons trapped within oxygen vacancies)onγ-Al_(2)O_(3).Notably,the content of Al_(penta)^(3+)was enriched to 18.3%.Then,the pre-established Pt Sn clusters were loaded.The electrons facilitated the formation of ultrafine Pt Sn nanoparticles(~2 nm),and the Al_(penta)^(3+)sites prevented the sintering of Pt Sn by constructing the strong Al_(penta)^(3+)–O–Sn bonds.Furthermore,the catalytic durability of the catalyst prepared by conventional impregnation methods was remarkably extended from 186 h for the color center-free sample to 1,000 h using the HAc–Al_(2)O_(3)support.This facile post-modification was further successfully extended to commercial Al_(2)O_(3)pellets without altering their mechanical properties,highlighting its potential in industrial applications.
基金National Natural Science Foundation of China(grant no.92261207,and NSFC Center for Single-Atom Catalysis under grant no.22388102)New Cornerstone Science Foundation.R.Q.acknowledges support from National Key R&D Program of China(2022YFA1504500)+2 种基金Young Scientists Fund of the National Natural Science Foundation of China(22202164)Natural Science Foundation of Fujian Province(2023J05006)Fundamental Research Funds for the Central Universities(20720230002).
文摘Surface modification of metallic nanocatalysts with organic ligands has emerged as an effective strategy to enhance catalytic selectivity,although offten at the expense of catalytic activity.In this study,we demonstrate a compelling approach by surface modifying Pd2S nanocrystals with PPhz ligands,resulting in a catalyst with excellent catalytic activity and durable selectivity for the semi-hydrogenation of terminal alkynes.Experimental and theoretical investigations reveal that the presence of S sites on the Pd surface directs PPh_(3) ligands to preferentially form covalent bonds with S,creating distinctive surface S=PPh_(3) motifs.This configuration induces a partial positive charge on Pd,facilitating hydrogen transfer and thus promoting catalytic activity.Furthermore,the covalent bond between the ligand and catalyst surface forms a robust network,ensuring ligand stability and increasing the hydrogenation energy barrier of olefins.Consequently,the Pd_(4)S@PPhz catalyst exhibits an improved catalytic selectivity with durability in terminal alkyne semi-hydrogenation.This study introduces an effective strategy for designing selective hydrogenation catalysts with an enhanced performance.
基金Project (No. 29974035) supported by the National Natural Science Foundation of China
文摘A new class of rhodium complexes with high catalytic activity as well as excellent stability, which was used as catalyst for carbonylation of methanol to acetic acid, is reported. It contains free donor (namely un-coordinated donor) atoms which enable to improve its stability by intramolecular substitution reaction. Its synthesis, characteristic and catalytic reaction were discussed here.
