All-perovskite tandem solar cells(ATSCs) have the potential to surpass the Shockley-Queisser efficiency limit of conventional single-junction devices. However, the performance and stability of mixed tin–lead(Sn–Pb) ...All-perovskite tandem solar cells(ATSCs) have the potential to surpass the Shockley-Queisser efficiency limit of conventional single-junction devices. However, the performance and stability of mixed tin–lead(Sn–Pb) perovskite solar cells(PSCs), which are crucial components of ATSCs, are much lower than those of lead-based perovskites. The primary challenges include the high crystallization rate of perovskite materials and the susceptibility of Sn^(2+) oxidation, which leads to rough morphology and unfavorable p-type self-doping. To address these issues, we introduced ethylhydrazine oxalate(EDO) at the perovskite interface, which effectively inhibits the oxidation of Sn^(2+) and simultaneously enhances the crystallinity of the perovskite. Consequently, the EDO-modified mixed tin-lead PSCs reached a power conversion efficiency(PCE) of 21.96% with high reproducibility. We further achieved a 27.58% efficient ATSCs by using EDO as interfacial passivator in the Sn-Pb PSCs.展开更多
The structure-performance relationship of Cu/Al_(2)O_(3) catalysts in the hydrogenation of diethyl oxalate(DEO)for the synthesis of alcohol ether esters has been investigated by various characterization techniques inc...The structure-performance relationship of Cu/Al_(2)O_(3) catalysts in the hydrogenation of diethyl oxalate(DEO)for the synthesis of alcohol ether esters has been investigated by various characterization techniques including XRD,XPS,N2O titration,and 27Al MAS-NMR.The results showed that when the crystal configurations of Al_(2)O_(3) were the same,increasing the specific surface area could effectively refine the size of copper nanoparticles(Cu NPs),and ultimately improve the conversion of DEO.Meanwhile,the smaller size ofγ-Al_(2)O_(3)(HSAl and SBAl)loaded Cu NPs promotes the reaction towards the deep hydrogenation to produce ethanol(EtOH)and ethylene glycol(EG).Besides,the larger size of Cu NPs on the surface of amorphous Al_(2)O_(3)(HTAl and SolAl)resulted in a lower conversion rate,where ethyl glycolate(Egly)is the main product.Despite there are differences in Al^(3+)ionic coordination in Al_(2)O_(3) with different crystal structures,the experimental data showed that the differences in Al^(3+)ionic coordination did not significantly affect the catalytic performance in the hydrogenation reaction.The formation of alcohol-ether ester chemicals is critically dependent on the interactions between Cu sites and acidic sites.Among them,EG and EtOH were dehydrated to form 2-ethoxyethanol via the SN2 mechanism,while Egly and EtOH were reacted to form ethyl ethoxyacetate(EEA)via the SN2 mechanism.This study provides a theoretical basis for the optimization of the coal-based glycol processes to achieve a diversified product portfolio.展开更多
Objective:Several therapeutic modalities for the prevention of calcium oxalate(CaOx)stones have been studied,but only a select few of these modalities have been incorporated into the American Urological Association gu...Objective:Several therapeutic modalities for the prevention of calcium oxalate(CaOx)stones have been studied,but only a select few of these modalities have been incorporated into the American Urological Association guidelines.Our study aimed to organize and interrogate existing research that may be promising for CaOx prevention.Methods:A literature search was conducted using MEDLINE and Embase from inception to November 16,2022.Our study population included adults with or without a history of CaOx kidney stones.Studies in which patients were treated with pharmacotherapies,herbal supplements,or uncategorized research chemicals that are not included in the current American Urological Association guidelines for preventing CaOx stones were included.Nonoriginal research was excluded.Results:Out of the 6155 identified articles,38 were included in the final analysis.The five distinct categories of interventions for stone prevention were“medications”,“herbal supplements”,“food and macronutrients”,“micronutrients”,and“enzymes and probiotics”.Modalities that were found to reduce known urinary risk factors were tolvaptan,cranberry juice,magnesium citrate,oxalate-degrading enzyme ALLN-177,and malic acid.Prophylaxis that reduced stone formation were sodium-glucose cotransporter-2 inhibitors,eicosapentaenoic acid,ethane-1-hydroxy-1,1-disphosphonate.Therapies that reduced urinary risk factors and stone formation were Phyllanthus niruri,rice bran,and magnesium hydroxide.Conclusion:Several of the identified therapies may provide prophylactic benefits for CaOx stone formation and may be useful for inclusion in guidelines for kidney stone prevention.展开更多
In this paper,the research progress of Cu-based catalyst and the activity enhancement strategies in the hydrogenation of dimethyl oxalate(DMO)to ethylene glycol(EG)was reviewed.As a green and economical ethylene glyco...In this paper,the research progress of Cu-based catalyst and the activity enhancement strategies in the hydrogenation of dimethyl oxalate(DMO)to ethylene glycol(EG)was reviewed.As a green and economical ethylene glycol production path,the core of DMO hydrogenation of EG lies in the rational design and optimization of catalysts.This paper first introduces the background of the DMO hydrogenation system EG significance and the important effect of Cu-based catalyst in the reaction,particularly emphasizing the coordination with the Cu^(+)-Cu^(0) species catalytic effect.Then,many factors affecting the activity of Cu-based catalysts were analyzed in detail,including the equilibrium effect between Cu^(0) and Cu+species,the surface dispersion of Cu species,the interaction between metal and support,and the morphology effect of the catalyst.Regarding strategies for improving catalyst performance,this paper summarized effective measures such as optimizing support structure,adding promoters and optimizing preparation methods,and demonstrated the practical application effects of these strategies through representative catalyst examples.In addition,this paper also discusses the complex relationship between the influencing factors and catalyst performance.It points out the key directions for future research,with in-depth exploration of the correlation between catalyst structure and performance,the development of new catalysts,and the application of machine learning and big data technology in the catalyst research and development.In summary,this paper provides comprehensive theoretical guidance and practical reference for the performance optimization of Cu-based catalysts for DMO hydrogenation to EG.展开更多
Oxalate content in spinach is a key trait of interest due to its relevance to human health.Understanding the genetic basis of it can facilitate the development of spinach varieties with reduced oxalate levels.In pursu...Oxalate content in spinach is a key trait of interest due to its relevance to human health.Understanding the genetic basis of it can facilitate the development of spinach varieties with reduced oxalate levels.In pursuit of understanding the genetic determinants,a diverse panel comprising 288 spinach accessions underwent thorough phenotyping of oxalate content and were subjected to whole-genome resequencing,resulting in a comprehensive dataset encompassing 14386 single-nucleotide polymorphisms(SNPs).Leveraging this dataset,we conducted a genome-wide association study(GWAS)to identify noteworthy SNPs associated with oxalate content.Furthermore,we employed genomic prediction(GP)via cross-prediction,utilizing five GP models,to assess genomic estimated breeding values(GEBVs)for oxalate content.The observed normal distribution and the wide range of oxalate content,exceeding 600.0 mg$100 g^(-1),underscore the complex and quantitative nature of this trait,likely influenced by multiple genes.Additionally,our analysis revealed distinct stratification,delineating the population into four discernible subpopulations.Furthermore,GWAS analysis employing five models in GAPIT 3 and TASSEL 5 unveiled nine significant SNPs(four SNPs on chromosome 1 and five on chromosome 5)associated with oxalate content.These loci exhibited associations with six candidate genes,which might have potential contribution to oxalate content regulation.Remarkably,our GP models exhibited notable predictive abilities,yielding average accuracies of up to 0.51 for GEBV estimation.The integration of GWAS and GP approaches offers a holistic comprehension of the genetic underpinnings of oxalate content in spinach.These findings offered a promising avenue for the development of spinach cultivars and hybrids optimized for oxalate levels,promoting consumer health.展开更多
Nano zero-valent iron(nZVI)is a promising phosphate adsorbent for advanced phosphate removal.However,the rapid passivation of nZVI and the low activity of adsorption sites seriously limit its phosphate removal perform...Nano zero-valent iron(nZVI)is a promising phosphate adsorbent for advanced phosphate removal.However,the rapid passivation of nZVI and the low activity of adsorption sites seriously limit its phosphate removal performance,accounting for its inapplicability to meet the emission criteria of 0.1 mg P/L phosphate.In this study,we report that the oxalate modification can inhibit the passivation of nZVI and alter the multi-stage phosphate adsorption mechanism by changing the adsorption sites.As expected,the stronger antipassivation ability of oxalate modified nZVI(OX-nZVI)strongly favored its phosphate adsorption.Interestingly,the oxalate modification endowed the surface Fe(III)sites with the lowest chemisorption energy and the fastest phosphate adsorption ability than the other adsorption sites,by in situ forming a Fe(III)-phosphate-oxalate ternary complex,therefore enabling an advanced phosphate removal process.At an initial phosphate concentration of 1.00 mg P/L,pH of 6.0 and a dosage of 0.3 g/L of adsorbents,OX-nZVI exhibited faster phosphate removal rate(0.11 g/mg/min)and lower residual phosphate level(0.02 mg P/L)than nZVI(0.055 g/mg/min and 0.19 mg P/L).This study sheds light on the importance of site manipulation in the development of high-performance adsorbents,and offers a facile surface modification strategy to prepare superior iron-basedmaterials for advanced phosphate removal.展开更多
The hydrogenation of dimethyl oxalate(DMO)to ethanol(Et OH)represents a promising avenue for syngas conversion and plays a pivotal role in advancing sustainable energy economies.Nevertheless,designing catalysts with h...The hydrogenation of dimethyl oxalate(DMO)to ethanol(Et OH)represents a promising avenue for syngas conversion and plays a pivotal role in advancing sustainable energy economies.Nevertheless,designing catalysts with high Et OH yields at low temperatures remains a significant challenge.This study introduces an efficient catalyst featuring a rich SiO_(2)-Ni_(3)Mo_(3)N interface,which achieved a remarkable 97.5%Et OH yield at 210°C and 2 MPa.Impressively,an Et OH yield of 95%was also obtained at 210°C and 1.5 MPa.The research demonstrates that the addition of SiO_(2)fosters the development of a rich SiO_(2)-Ni_(3)Mo_(3)N interface,which enhances the concentration of Lewis acid sites(L-acid)and Brønsted acids sites(B-acid)within the catalyst.This enhancement promotes the adsorption of raw material and intermediate products while increasing H_(2)adsorption,thereby boosting the catalyst's deep hydrogenation capacity.Density functional theory(DFT)simulations indicate that SiO2incorporation modifies the catalyst's metal d-band center through electron transfer,increasing its adsorption capability for raw materials and intermediates and facilitating Et OH production.Consequently,this study achieves high Et OH yields at low temperatures,advances the industrialization process of syngas to Et OH conversion,and offers novel insights into constructing highly active catalytic interfaces for DMO hydrogenation.展开更多
Lanthanum oxalate hydrate La2（C2O4）3·10H2O,the precursor of La2O3 ultrafine powders,was prepared by impinging stream reactor method with PEG 20000 as surfactant.Thermal decomposition of La2（C2O4）3·10H2O ...Lanthanum oxalate hydrate La2（C2O4）3·10H2O,the precursor of La2O3 ultrafine powders,was prepared by impinging stream reactor method with PEG 20000 as surfactant.Thermal decomposition of La2（C2O4）3·10H2O from room temperature to 900 °C was investigated and intermediates and final solid products were characterized by FTIR and DSC-TG.Results show that the thermal decomposition process consists of five consecutive stage reactions.Flynn-Wall-Ozawa（FWO） and Kissinger-Akahira-Sunose（KAS） methods were implemented for the calculation of energy of activation（E）,and the results show that E depends on α,demonstrating that the decomposition reaction process of the lanthanum oxalate is of a complex kinetic mechanism.The most probable mechanistic function,G（α）=[1-（1＋α）1/3]2,and the kinetic parameters were obtained by multivariate non-linear regression analysis method.The average E-value that is compatible with the kinetic model is close to value which was obtained by FWO and KAS methods.The fitting curve matches the original TG curve very well.展开更多
Nanometer-size zero-valent iron(NZVI)is an efficient reducing agent,but its surface is easily passivated with an oxide layer,leading to reaction inefficiency.In our study,oxalate(OA)was introduced into this heterogene...Nanometer-size zero-valent iron(NZVI)is an efficient reducing agent,but its surface is easily passivated with an oxide layer,leading to reaction inefficiency.In our study,oxalate(OA)was introduced into this heterogeneous system of NZVI,which could form ferrioxalate complexes with the NZVI surface-bound Fe3+and dissolved Fe3+in the solution.Photolysis of ferrioxalate complexes can facilitate the generation of Fe2+from Fe3+and CO_(2)·-radical,both species have strong reduction capacity.Hence,a"photo-oxalate-Fe(0)"system through sunlight induction was established,which not only prohibited the formation of a surface passivation layer,but also displayed a synergetic mechanism of ferrioxalate photolysis to enhance reduction,exhibiting remarkably higher degradation activity(several times faster)toward the model pollutant Cr(Ⅵ)than the mechanism with NZVI alone.Factor tests suggested that both NZVI dosage and OA content markedly affected the reduction rate.Low pH was beneficial to the reduction efficiency.Moreover,recyclability experiment showed that the reduction rate decreased from 0.21706 to 0.03977 min-1 after three cycles of reuse due to the NZVI losing reaction activity generally,but the system still maintained considerable reduction capacity.Finally,a mechanism was revealed whereby NZVI would transform to Fe oxides after the exhaustion of its reductive power,and the photolysis of ferrioxalate to promote the cycling of iron species played the predominant role in providing extra reduction ability.These features confirm that introduction of OA into Cr(Ⅵ)reduction by NZVI through sunlight induction is advantageous and promising.展开更多
Diphenyl oxalate was synthesized from transesterification of dimethyl oxalate with phenol over TS-1 ( 2.5 wt% Ti ) catalyst. TS-1 catalyst, as a heterogeneous catalyst, showed excellent selectivity of diphenyl oxalat...Diphenyl oxalate was synthesized from transesterification of dimethyl oxalate with phenol over TS-1 ( 2.5 wt% Ti ) catalyst. TS-1 catalyst, as a heterogeneous catalyst, showed excellent selectivity of diphenyl oxalate and methylphenyl oxalate compared with other homogeneous catalysts. Lewis acid sites on TS-1 catalyst were the active sites for transesterification of dimethyl oxalate with phenol. The high selectivity was closely related to the weak acid sites over TS-1.展开更多
Hierarchical europium oxalate Eu2（C2O4）3.10H2O micro-particles were synthesized through a simple precipitation method at room temperature in present of trisodium citrate. The products were characterized by X-ray dif...Hierarchical europium oxalate Eu2（C2O4）3.10H2O micro-particles were synthesized through a simple precipitation method at room temperature in present of trisodium citrate. The products were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, field-emission scanning electron microscopy, and photoluminescence. The possible formation mechanism of the hierarchical europium oxalate Eu2（C2O4）3.10H2O micro-particles was discussed.展开更多
Peroxyoxalate chemiluminescence was, for the first time, examined by using ternary mixed solutions of water-hydrophilic/hydrophobic organic solvent. Eosin Y as a model fluorescence compound was dissolved with the tern...Peroxyoxalate chemiluminescence was, for the first time, examined by using ternary mixed solutions of water-hydrophilic/hydrophobic organic solvent. Eosin Y as a model fluorescence compound was dissolved with the ternary solutions of water (1.0 mM carbonate buffer, pH 9.0)-acetonitrile-ethyl acetate, water-rich of 15:3:2 volume ratio and organic solvent-rich of 3:8:4 volume ratio, to which bis(2,4,6-trichlorophenyl) oxalate and hydrogen peroxide chemiluminescence reagent were added. The chemiluminescence observed with the ternary solutions, especially the organic solvent-rich solution, showed a larger signal than that observed with the water only solution or water-acetonitrile mixed solution. Chemiluminescence in the presence of twenty types of α-amino acid was similarly examined by using the ternary organic solvent-rich solution. The chemiluminescence of three α-amino acids with fluorescence properties was enhanced with the ternary solution. The data reported here may contribute to development of a new, sensitive peroxyoxalate chemiluminescence detection system.展开更多
Methyl glycolate is a good solvent and can be used as feedstock for the synthesis of some important organic chemicals. Catalytic hydrogenation of dimethyl oxalate （DMO） over copper-silver catalyst supported on silic...Methyl glycolate is a good solvent and can be used as feedstock for the synthesis of some important organic chemicals. Catalytic hydrogenation of dimethyl oxalate （DMO） over copper-silver catalyst supported on silica was studied. The Cu-Ag/SiO2 catalyst supported on silica sol was prepared by homogeneous deposition-precipitation of the mixture of aqueous euprammonia complex and silica sol. The proper active temperature of Cu-Ag/SiO2 catalyst for hydrogenation of DMO was 523-623 K. The most preferable reaction conditions for methyl glycolate （MG） were optimized： temperature at 468-478 K, 40-60 mesh catalyst diameter, H2/DMO ratio 40, and 1.0 h^-1 of LHSV.展开更多
Cu/SiO2 catalysts prepared by a convenient and efficient method using the urea hydrolysis deposition-precipitation （UHDP） technique have been proposed focusing on the effect of copper loading.The texture,structure a...Cu/SiO2 catalysts prepared by a convenient and efficient method using the urea hydrolysis deposition-precipitation （UHDP） technique have been proposed focusing on the effect of copper loading.The texture,structure and composition are systematically characterized by ICP,FTIR,N 2-physisorption,N2O chemisorption,TPR,XRD and XPS.The formation of copper phyllosilicate is observed in Cu/SiO2 catalyst by adopting UHDP method,and the amount of copper phyllosilicate is related to copper loading.It is found the structure properties and catalytic performance is profoundly affected by the amount of copper phyllosilicate.The excellent catalytic activity is attributed to the synergetic effect between Cu0 and Cu ＋.DMO conversion and EG selectivity are determined by the amount of Cu0 and Cu＋,respectively.The proper copper loading （30 wt%） provides with the highest ratio of Cu ＋ /Cu0,giving rise to the highest EG yield of 95% under the reaction conditions of p=2.0 MPa,T=473 K,H2/DMO=80 and LHSV=1.0h-1.展开更多
High purity Y_2O_3 nano-powders was synthesized directly from solution ofindustrial YCl_3 by method of oxalate precipitation through super-micro-reactors made by complexnon-ionic surfactant. The purity and diameter of...High purity Y_2O_3 nano-powders was synthesized directly from solution ofindustrial YCl_3 by method of oxalate precipitation through super-micro-reactors made by complexnon-ionic surfactant. The purity and diameter of Y_2O_3 particles were controlled by such processingparameters as concentration of YCl_3 and oxalic acid and complex non-ionic surfactant etc. TEMphotomicrographs show that Y_2O_3 particles are spherical in shape, with an average diameter of lessthan 30 nm. Test results certify that the purity and particle diameter as well as the dispersion ofY_2O_3 nano-powder depend on the concentrations of YCl_3, oxalic acid and complex non-ionicsurfactant. The optimum ranges of the concentrations for YCl_3 and complex non-ionic surfactant whenthe diameter of Y_2O_3 particles is smaller than 100 nm are 0.43 ～1.4 mol ? L^(-1) and0.031～0.112 mol·L^(-1) respectively, while the mass fraction range of oxalic acid is 10% ～18% .The purity of Y_2O_3 nano-powder tested by ICP-AES analysis is 99.99% .展开更多
Silver-ceramics (Ag2MO2)(M=Co, Ni, or Cu) were prepared through thermal decompositionof coprecipitated oxalates. Pellets of these materials were annealed at 350℃ for different timeperiods up to 5 h. The effect of ann...Silver-ceramics (Ag2MO2)(M=Co, Ni, or Cu) were prepared through thermal decompositionof coprecipitated oxalates. Pellets of these materials were annealed at 350℃ for different timeperiods up to 5 h. The effect of annealing time on the transport properties was studied. IR andX-ray spectra were also studied.展开更多
The formation kinetics and mechanism of tricalcium aluminate hydrate and calcium oxalate in dilute sodium aluminate solution and sodium oxalate solution were studied respectively based on the lime causticization, and ...The formation kinetics and mechanism of tricalcium aluminate hydrate and calcium oxalate in dilute sodium aluminate solution and sodium oxalate solution were studied respectively based on the lime causticization, and the optimal conditions for removing the oxalate in dilute sodium aluminate solution as well as the mechanism were finally obtained.The formation processes of tricalcium aluminate hydrate and calcium oxalate are mainly controlled by the chemical reaction and the inner diffusion respectively,and the corresponding reaction rate equations as well as the apparent activation energy were calculated. The hydrocalumite with a spatially interleaved structure will form in dilute sodium aluminate solution with sodium oxalate, greatly removing the oxalate impurity by absorption. Calcium oxalate can be converted to tricalcium aluminate hydrate with the increasing reaction time. The oxalate causticization efficiency and the alumina loss rate can be over 90% and below 31% respectively when reacted at 50℃ with a stirring rate of 200 r/min.展开更多
The Cu/SiO_2 catalysts were in situ synthesized by the hydrolysis of tetraethyl orthosilicate（TEOS） in one phase solution using ethanol as co-solvent or TEOS/H_2O two phases solution,followed by the precipitation of...The Cu/SiO_2 catalysts were in situ synthesized by the hydrolysis of tetraethyl orthosilicate（TEOS） in one phase solution using ethanol as co-solvent or TEOS/H_2O two phases solution,followed by the precipitation of copper on SiO_2 by ammonia evaporation. In the hydrogenation of dimethyl oxalate,the catalyst prepared by one phase hydrolysis exhibited higher activity and ethylene glycol（EG） selectivity at lower temperature than that of two phases due to its larger BET surface area and multimodal pore distribution.At 488-503 K,the catalyst prepared in one phase solution with water/ethanol（W/E） volume ratio of 3：1 exhibited 90- 95%EG selectivity,while catalyst prepared by two phase hydrolysis reached 90%EG selectivity only at 498-503 K.展开更多
CO oxidative coupling to dimethyl oxalate(DMO) is the most crucial step in coal to ethylene glycol. Pdbased supported catalysts have been verified effective for generating DMO, but concomitant generation of dimethyl c...CO oxidative coupling to dimethyl oxalate(DMO) is the most crucial step in coal to ethylene glycol. Pdbased supported catalysts have been verified effective for generating DMO, but concomitant generation of dimethyl carbonate(DMC) is always unavoidable. It is generally accepted that Pd(0) is the active species for producing DMO, while Pd(II) for DMC. However, density functional theory calculations have proposed that the selectivity to DMO or DMC highly depends on the space state of Pd species rather than its oxidative state. It is thus urgently desired to develop high-efficient catalysts with well-defined structure,and further to elucidate the structure-performance relationship. In this work, HKUST-1 with unique structure of paired-Cu(Ⅱ) centers was chosen as ideal support to construct the catalysts with respective paired-Pd(Ⅱ) centers and isolated-Pd(Ⅱ) centers via in situ Pd species doping. In despite of featuring Pdδ+(δ≈2) oxidation state, the synthesized paired-Pd(Ⅱ)/HKUST-1 catalyst still exhibited DMO as dominant product(90.8% of DMO selectivity). For isolated-Pd(Ⅱ)/HKUST-1 catalyst, however, the main product was DMC(84.8% of DMC selectivity). Based on catalyst characterizations, the structures of paired-Pd(Ⅱ) centers and isolated-Pd(Ⅱ) centers were determined. DMO was generated from the coupling of adjacent *COOCH;intermediates adsorbed on paired-Pd(Ⅱ) centers, while DMC was produced from the reaction between methyl nitrite and the *COOCH;intermediates formed on isolated-Pd(Ⅱ) centers. Current work is the first MOFs-based catalyst with well-defined structure being applied in CO oxidative coupling reaction, which not only sheds light on the structure-performance relationship, but also inspires the potential of using MOFs as tunable platform to design high-efficient catalysts in heterogeneous catalysis.展开更多
The precipitation performance and kinetics of gibbsite from sodium aluminate solution with different sodium oxalate concentrations as well as the corresponding influence mechanism of oxalate during the seed precipitat...The precipitation performance and kinetics of gibbsite from sodium aluminate solution with different sodium oxalate concentrations as well as the corresponding influence mechanism of oxalate during the seed precipitation process were systematically investigated by physicochemical properties test,using SEM and Raman spectra.As the concentration of sodium oxalate increases,both the precipitation rate and particle size of gibbsite decrease.The presence of sodium oxalate not only increases the viscosity of sodium aluminate solution,but also promotes the transformation of Al(OH)4^? to Al2O(OH)6^2?.The overall reaction rate constant decreases and the apparent activation energy of gibbsite increases with the increasing sodium oxalate concentration,the rate controlling step of which is chemical reaction.The needle-like sodium oxalate precipitates on the gibbsite crystals and covers the active Al(OH)3 seed sites,which leads to the lower precipitation rate and the finer particle size of gibbsite during the seed precipitation process.展开更多
基金financially supported by National Key R&D Program of China (2025YFE0100300)the National Natural Science Foundation of China (52202293 and 52330004)the Fundamental Research Funds for the Central Universities (WUT: 2023IVA075 and 2023IVB009)。
文摘All-perovskite tandem solar cells(ATSCs) have the potential to surpass the Shockley-Queisser efficiency limit of conventional single-junction devices. However, the performance and stability of mixed tin–lead(Sn–Pb) perovskite solar cells(PSCs), which are crucial components of ATSCs, are much lower than those of lead-based perovskites. The primary challenges include the high crystallization rate of perovskite materials and the susceptibility of Sn^(2+) oxidation, which leads to rough morphology and unfavorable p-type self-doping. To address these issues, we introduced ethylhydrazine oxalate(EDO) at the perovskite interface, which effectively inhibits the oxidation of Sn^(2+) and simultaneously enhances the crystallinity of the perovskite. Consequently, the EDO-modified mixed tin-lead PSCs reached a power conversion efficiency(PCE) of 21.96% with high reproducibility. We further achieved a 27.58% efficient ATSCs by using EDO as interfacial passivator in the Sn-Pb PSCs.
文摘The structure-performance relationship of Cu/Al_(2)O_(3) catalysts in the hydrogenation of diethyl oxalate(DEO)for the synthesis of alcohol ether esters has been investigated by various characterization techniques including XRD,XPS,N2O titration,and 27Al MAS-NMR.The results showed that when the crystal configurations of Al_(2)O_(3) were the same,increasing the specific surface area could effectively refine the size of copper nanoparticles(Cu NPs),and ultimately improve the conversion of DEO.Meanwhile,the smaller size ofγ-Al_(2)O_(3)(HSAl and SBAl)loaded Cu NPs promotes the reaction towards the deep hydrogenation to produce ethanol(EtOH)and ethylene glycol(EG).Besides,the larger size of Cu NPs on the surface of amorphous Al_(2)O_(3)(HTAl and SolAl)resulted in a lower conversion rate,where ethyl glycolate(Egly)is the main product.Despite there are differences in Al^(3+)ionic coordination in Al_(2)O_(3) with different crystal structures,the experimental data showed that the differences in Al^(3+)ionic coordination did not significantly affect the catalytic performance in the hydrogenation reaction.The formation of alcohol-ether ester chemicals is critically dependent on the interactions between Cu sites and acidic sites.Among them,EG and EtOH were dehydrated to form 2-ethoxyethanol via the SN2 mechanism,while Egly and EtOH were reacted to form ethyl ethoxyacetate(EEA)via the SN2 mechanism.This study provides a theoretical basis for the optimization of the coal-based glycol processes to achieve a diversified product portfolio.
文摘Objective:Several therapeutic modalities for the prevention of calcium oxalate(CaOx)stones have been studied,but only a select few of these modalities have been incorporated into the American Urological Association guidelines.Our study aimed to organize and interrogate existing research that may be promising for CaOx prevention.Methods:A literature search was conducted using MEDLINE and Embase from inception to November 16,2022.Our study population included adults with or without a history of CaOx kidney stones.Studies in which patients were treated with pharmacotherapies,herbal supplements,or uncategorized research chemicals that are not included in the current American Urological Association guidelines for preventing CaOx stones were included.Nonoriginal research was excluded.Results:Out of the 6155 identified articles,38 were included in the final analysis.The five distinct categories of interventions for stone prevention were“medications”,“herbal supplements”,“food and macronutrients”,“micronutrients”,and“enzymes and probiotics”.Modalities that were found to reduce known urinary risk factors were tolvaptan,cranberry juice,magnesium citrate,oxalate-degrading enzyme ALLN-177,and malic acid.Prophylaxis that reduced stone formation were sodium-glucose cotransporter-2 inhibitors,eicosapentaenoic acid,ethane-1-hydroxy-1,1-disphosphonate.Therapies that reduced urinary risk factors and stone formation were Phyllanthus niruri,rice bran,and magnesium hydroxide.Conclusion:Several of the identified therapies may provide prophylactic benefits for CaOx stone formation and may be useful for inclusion in guidelines for kidney stone prevention.
基金supported by Guangxi Science and Technology Major Program(GuikeAA23062018)the Academic Newcomer Award Project of Guangxi University(2025GXUXSXR07)。
文摘In this paper,the research progress of Cu-based catalyst and the activity enhancement strategies in the hydrogenation of dimethyl oxalate(DMO)to ethylene glycol(EG)was reviewed.As a green and economical ethylene glycol production path,the core of DMO hydrogenation of EG lies in the rational design and optimization of catalysts.This paper first introduces the background of the DMO hydrogenation system EG significance and the important effect of Cu-based catalyst in the reaction,particularly emphasizing the coordination with the Cu^(+)-Cu^(0) species catalytic effect.Then,many factors affecting the activity of Cu-based catalysts were analyzed in detail,including the equilibrium effect between Cu^(0) and Cu+species,the surface dispersion of Cu species,the interaction between metal and support,and the morphology effect of the catalyst.Regarding strategies for improving catalyst performance,this paper summarized effective measures such as optimizing support structure,adding promoters and optimizing preparation methods,and demonstrated the practical application effects of these strategies through representative catalyst examples.In addition,this paper also discusses the complex relationship between the influencing factors and catalyst performance.It points out the key directions for future research,with in-depth exploration of the correlation between catalyst structure and performance,the development of new catalysts,and the application of machine learning and big data technology in the catalyst research and development.In summary,this paper provides comprehensive theoretical guidance and practical reference for the performance optimization of Cu-based catalysts for DMO hydrogenation to EG.
基金supported by USDA-SCRI(Grant Nos.2017-51181-26830 and 2023-51181-41321)USDA-AMS SCMP(Grant No.16SCCMAR0001)+1 种基金Arkansas Department of Agriculture SCBGP(Grant No.AM22SCBGPAR1130-00)USDA NIFA Hatch project(Grant Nos.ARK0VG2018 and ARK02440).
文摘Oxalate content in spinach is a key trait of interest due to its relevance to human health.Understanding the genetic basis of it can facilitate the development of spinach varieties with reduced oxalate levels.In pursuit of understanding the genetic determinants,a diverse panel comprising 288 spinach accessions underwent thorough phenotyping of oxalate content and were subjected to whole-genome resequencing,resulting in a comprehensive dataset encompassing 14386 single-nucleotide polymorphisms(SNPs).Leveraging this dataset,we conducted a genome-wide association study(GWAS)to identify noteworthy SNPs associated with oxalate content.Furthermore,we employed genomic prediction(GP)via cross-prediction,utilizing five GP models,to assess genomic estimated breeding values(GEBVs)for oxalate content.The observed normal distribution and the wide range of oxalate content,exceeding 600.0 mg$100 g^(-1),underscore the complex and quantitative nature of this trait,likely influenced by multiple genes.Additionally,our analysis revealed distinct stratification,delineating the population into four discernible subpopulations.Furthermore,GWAS analysis employing five models in GAPIT 3 and TASSEL 5 unveiled nine significant SNPs(four SNPs on chromosome 1 and five on chromosome 5)associated with oxalate content.These loci exhibited associations with six candidate genes,which might have potential contribution to oxalate content regulation.Remarkably,our GP models exhibited notable predictive abilities,yielding average accuracies of up to 0.51 for GEBV estimation.The integration of GWAS and GP approaches offers a holistic comprehension of the genetic underpinnings of oxalate content in spinach.These findings offered a promising avenue for the development of spinach cultivars and hybrids optimized for oxalate levels,promoting consumer health.
基金supported by the National Key Research and Development Program of China(Nos.2022YFA1205602,and 2023YFC3707801)the National Natural Science Foundation of China(Nos.U22A20402,22376073,21936003 and 22306119)China Postdoctoral Science Foundation(No.2023T160419).
文摘Nano zero-valent iron(nZVI)is a promising phosphate adsorbent for advanced phosphate removal.However,the rapid passivation of nZVI and the low activity of adsorption sites seriously limit its phosphate removal performance,accounting for its inapplicability to meet the emission criteria of 0.1 mg P/L phosphate.In this study,we report that the oxalate modification can inhibit the passivation of nZVI and alter the multi-stage phosphate adsorption mechanism by changing the adsorption sites.As expected,the stronger antipassivation ability of oxalate modified nZVI(OX-nZVI)strongly favored its phosphate adsorption.Interestingly,the oxalate modification endowed the surface Fe(III)sites with the lowest chemisorption energy and the fastest phosphate adsorption ability than the other adsorption sites,by in situ forming a Fe(III)-phosphate-oxalate ternary complex,therefore enabling an advanced phosphate removal process.At an initial phosphate concentration of 1.00 mg P/L,pH of 6.0 and a dosage of 0.3 g/L of adsorbents,OX-nZVI exhibited faster phosphate removal rate(0.11 g/mg/min)and lower residual phosphate level(0.02 mg P/L)than nZVI(0.055 g/mg/min and 0.19 mg P/L).This study sheds light on the importance of site manipulation in the development of high-performance adsorbents,and offers a facile surface modification strategy to prepare superior iron-basedmaterials for advanced phosphate removal.
基金the financial support from the National Natural Science Foundation of China(No.21962015)the Bingtuan Graduate Innovation Project 2024(No.BTYJXM-2024-K12)。
文摘The hydrogenation of dimethyl oxalate(DMO)to ethanol(Et OH)represents a promising avenue for syngas conversion and plays a pivotal role in advancing sustainable energy economies.Nevertheless,designing catalysts with high Et OH yields at low temperatures remains a significant challenge.This study introduces an efficient catalyst featuring a rich SiO_(2)-Ni_(3)Mo_(3)N interface,which achieved a remarkable 97.5%Et OH yield at 210°C and 2 MPa.Impressively,an Et OH yield of 95%was also obtained at 210°C and 1.5 MPa.The research demonstrates that the addition of SiO_(2)fosters the development of a rich SiO_(2)-Ni_(3)Mo_(3)N interface,which enhances the concentration of Lewis acid sites(L-acid)and Brønsted acids sites(B-acid)within the catalyst.This enhancement promotes the adsorption of raw material and intermediate products while increasing H_(2)adsorption,thereby boosting the catalyst's deep hydrogenation capacity.Density functional theory(DFT)simulations indicate that SiO2incorporation modifies the catalyst's metal d-band center through electron transfer,increasing its adsorption capability for raw materials and intermediates and facilitating Et OH production.Consequently,this study achieves high Et OH yields at low temperatures,advances the industrialization process of syngas to Et OH conversion,and offers novel insights into constructing highly active catalytic interfaces for DMO hydrogenation.
基金Project (IRT0974) supported by Program for Changjiang Scholars and Innovative Research Team in University,ChinaProject (50974098) supported by the National Natural Science Foundation of China
文摘Lanthanum oxalate hydrate La2（C2O4）3·10H2O,the precursor of La2O3 ultrafine powders,was prepared by impinging stream reactor method with PEG 20000 as surfactant.Thermal decomposition of La2（C2O4）3·10H2O from room temperature to 900 °C was investigated and intermediates and final solid products were characterized by FTIR and DSC-TG.Results show that the thermal decomposition process consists of five consecutive stage reactions.Flynn-Wall-Ozawa（FWO） and Kissinger-Akahira-Sunose（KAS） methods were implemented for the calculation of energy of activation（E）,and the results show that E depends on α,demonstrating that the decomposition reaction process of the lanthanum oxalate is of a complex kinetic mechanism.The most probable mechanistic function,G（α）=[1-（1＋α）1/3]2,and the kinetic parameters were obtained by multivariate non-linear regression analysis method.The average E-value that is compatible with the kinetic model is close to value which was obtained by FWO and KAS methods.The fitting curve matches the original TG curve very well.
基金supported by Project funded by China Postdoctoral Science Foundation(No.2017M611533)
文摘Nanometer-size zero-valent iron(NZVI)is an efficient reducing agent,but its surface is easily passivated with an oxide layer,leading to reaction inefficiency.In our study,oxalate(OA)was introduced into this heterogeneous system of NZVI,which could form ferrioxalate complexes with the NZVI surface-bound Fe3+and dissolved Fe3+in the solution.Photolysis of ferrioxalate complexes can facilitate the generation of Fe2+from Fe3+and CO_(2)·-radical,both species have strong reduction capacity.Hence,a"photo-oxalate-Fe(0)"system through sunlight induction was established,which not only prohibited the formation of a surface passivation layer,but also displayed a synergetic mechanism of ferrioxalate photolysis to enhance reduction,exhibiting remarkably higher degradation activity(several times faster)toward the model pollutant Cr(Ⅵ)than the mechanism with NZVI alone.Factor tests suggested that both NZVI dosage and OA content markedly affected the reduction rate.Low pH was beneficial to the reduction efficiency.Moreover,recyclability experiment showed that the reduction rate decreased from 0.21706 to 0.03977 min-1 after three cycles of reuse due to the NZVI losing reaction activity generally,but the system still maintained considerable reduction capacity.Finally,a mechanism was revealed whereby NZVI would transform to Fe oxides after the exhaustion of its reductive power,and the photolysis of ferrioxalate to promote the cycling of iron species played the predominant role in providing extra reduction ability.These features confirm that introduction of OA into Cr(Ⅵ)reduction by NZVI through sunlight induction is advantageous and promising.
基金This work was supported by the National Natural Science Foundation of China(20276050)Foundation for University Key Teacher by the Ministry of Educationthe Department of Science and Technology of Yunnan Province for the project on Technology Collaboration and Development in China.
文摘Diphenyl oxalate was synthesized from transesterification of dimethyl oxalate with phenol over TS-1 ( 2.5 wt% Ti ) catalyst. TS-1 catalyst, as a heterogeneous catalyst, showed excellent selectivity of diphenyl oxalate and methylphenyl oxalate compared with other homogeneous catalysts. Lewis acid sites on TS-1 catalyst were the active sites for transesterification of dimethyl oxalate with phenol. The high selectivity was closely related to the weak acid sites over TS-1.
文摘Hierarchical europium oxalate Eu2（C2O4）3.10H2O micro-particles were synthesized through a simple precipitation method at room temperature in present of trisodium citrate. The products were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, field-emission scanning electron microscopy, and photoluminescence. The possible formation mechanism of the hierarchical europium oxalate Eu2（C2O4）3.10H2O micro-particles was discussed.
文摘Peroxyoxalate chemiluminescence was, for the first time, examined by using ternary mixed solutions of water-hydrophilic/hydrophobic organic solvent. Eosin Y as a model fluorescence compound was dissolved with the ternary solutions of water (1.0 mM carbonate buffer, pH 9.0)-acetonitrile-ethyl acetate, water-rich of 15:3:2 volume ratio and organic solvent-rich of 3:8:4 volume ratio, to which bis(2,4,6-trichlorophenyl) oxalate and hydrogen peroxide chemiluminescence reagent were added. The chemiluminescence observed with the ternary solutions, especially the organic solvent-rich solution, showed a larger signal than that observed with the water only solution or water-acetonitrile mixed solution. Chemiluminescence in the presence of twenty types of α-amino acid was similarly examined by using the ternary organic solvent-rich solution. The chemiluminescence of three α-amino acids with fluorescence properties was enhanced with the ternary solution. The data reported here may contribute to development of a new, sensitive peroxyoxalate chemiluminescence detection system.
文摘Methyl glycolate is a good solvent and can be used as feedstock for the synthesis of some important organic chemicals. Catalytic hydrogenation of dimethyl oxalate （DMO） over copper-silver catalyst supported on silica was studied. The Cu-Ag/SiO2 catalyst supported on silica sol was prepared by homogeneous deposition-precipitation of the mixture of aqueous euprammonia complex and silica sol. The proper active temperature of Cu-Ag/SiO2 catalyst for hydrogenation of DMO was 523-623 K. The most preferable reaction conditions for methyl glycolate （MG） were optimized： temperature at 468-478 K, 40-60 mesh catalyst diameter, H2/DMO ratio 40, and 1.0 h^-1 of LHSV.
文摘Cu/SiO2 catalysts prepared by a convenient and efficient method using the urea hydrolysis deposition-precipitation （UHDP） technique have been proposed focusing on the effect of copper loading.The texture,structure and composition are systematically characterized by ICP,FTIR,N 2-physisorption,N2O chemisorption,TPR,XRD and XPS.The formation of copper phyllosilicate is observed in Cu/SiO2 catalyst by adopting UHDP method,and the amount of copper phyllosilicate is related to copper loading.It is found the structure properties and catalytic performance is profoundly affected by the amount of copper phyllosilicate.The excellent catalytic activity is attributed to the synergetic effect between Cu0 and Cu ＋.DMO conversion and EG selectivity are determined by the amount of Cu0 and Cu＋,respectively.The proper copper loading （30 wt%） provides with the highest ratio of Cu ＋ /Cu0,giving rise to the highest EG yield of 95% under the reaction conditions of p=2.0 MPa,T=473 K,H2/DMO=80 and LHSV=1.0h-1.
文摘High purity Y_2O_3 nano-powders was synthesized directly from solution ofindustrial YCl_3 by method of oxalate precipitation through super-micro-reactors made by complexnon-ionic surfactant. The purity and diameter of Y_2O_3 particles were controlled by such processingparameters as concentration of YCl_3 and oxalic acid and complex non-ionic surfactant etc. TEMphotomicrographs show that Y_2O_3 particles are spherical in shape, with an average diameter of lessthan 30 nm. Test results certify that the purity and particle diameter as well as the dispersion ofY_2O_3 nano-powder depend on the concentrations of YCl_3, oxalic acid and complex non-ionicsurfactant. The optimum ranges of the concentrations for YCl_3 and complex non-ionic surfactant whenthe diameter of Y_2O_3 particles is smaller than 100 nm are 0.43 ～1.4 mol ? L^(-1) and0.031～0.112 mol·L^(-1) respectively, while the mass fraction range of oxalic acid is 10% ～18% .The purity of Y_2O_3 nano-powder tested by ICP-AES analysis is 99.99% .
文摘Silver-ceramics (Ag2MO2)(M=Co, Ni, or Cu) were prepared through thermal decompositionof coprecipitated oxalates. Pellets of these materials were annealed at 350℃ for different timeperiods up to 5 h. The effect of annealing time on the transport properties was studied. IR andX-ray spectra were also studied.
基金Project(2018YFC1901903)supported by the National Key R&D Program of ChinaProjects(51774079,51674075)supported by the National Natural Science Foundation of ChinaProject(N182508026)supported by the Fundamental Research Funds for the Central Universities,China
文摘The formation kinetics and mechanism of tricalcium aluminate hydrate and calcium oxalate in dilute sodium aluminate solution and sodium oxalate solution were studied respectively based on the lime causticization, and the optimal conditions for removing the oxalate in dilute sodium aluminate solution as well as the mechanism were finally obtained.The formation processes of tricalcium aluminate hydrate and calcium oxalate are mainly controlled by the chemical reaction and the inner diffusion respectively,and the corresponding reaction rate equations as well as the apparent activation energy were calculated. The hydrocalumite with a spatially interleaved structure will form in dilute sodium aluminate solution with sodium oxalate, greatly removing the oxalate impurity by absorption. Calcium oxalate can be converted to tricalcium aluminate hydrate with the increasing reaction time. The oxalate causticization efficiency and the alumina loss rate can be over 90% and below 31% respectively when reacted at 50℃ with a stirring rate of 200 r/min.
基金supported by the International Science and Technology Cooperation Program(No 2009DFA61050)National High Technology Research and Development Program of China(863 program)(Nos 2007AA05Z334 & 2009AA05Z407)National Basic Research Program of China(No2007CB210200)
文摘The Cu/SiO_2 catalysts were in situ synthesized by the hydrolysis of tetraethyl orthosilicate（TEOS） in one phase solution using ethanol as co-solvent or TEOS/H_2O two phases solution,followed by the precipitation of copper on SiO_2 by ammonia evaporation. In the hydrogenation of dimethyl oxalate,the catalyst prepared by one phase hydrolysis exhibited higher activity and ethylene glycol（EG） selectivity at lower temperature than that of two phases due to its larger BET surface area and multimodal pore distribution.At 488-503 K,the catalyst prepared in one phase solution with water/ethanol（W/E） volume ratio of 3：1 exhibited 90- 95%EG selectivity,while catalyst prepared by two phase hydrolysis reached 90%EG selectivity only at 498-503 K.
基金supported by the National Key Research and Development Program of China(2017YFA0206802,2017YFA0700103,2018YFA0704500)the Programs of the Chinese Academy of Sciences(QYZDJ-SSW-SLH028)the Natural Science Foundation of Shandong Province(ZR2020QB051)。
文摘CO oxidative coupling to dimethyl oxalate(DMO) is the most crucial step in coal to ethylene glycol. Pdbased supported catalysts have been verified effective for generating DMO, but concomitant generation of dimethyl carbonate(DMC) is always unavoidable. It is generally accepted that Pd(0) is the active species for producing DMO, while Pd(II) for DMC. However, density functional theory calculations have proposed that the selectivity to DMO or DMC highly depends on the space state of Pd species rather than its oxidative state. It is thus urgently desired to develop high-efficient catalysts with well-defined structure,and further to elucidate the structure-performance relationship. In this work, HKUST-1 with unique structure of paired-Cu(Ⅱ) centers was chosen as ideal support to construct the catalysts with respective paired-Pd(Ⅱ) centers and isolated-Pd(Ⅱ) centers via in situ Pd species doping. In despite of featuring Pdδ+(δ≈2) oxidation state, the synthesized paired-Pd(Ⅱ)/HKUST-1 catalyst still exhibited DMO as dominant product(90.8% of DMO selectivity). For isolated-Pd(Ⅱ)/HKUST-1 catalyst, however, the main product was DMC(84.8% of DMC selectivity). Based on catalyst characterizations, the structures of paired-Pd(Ⅱ) centers and isolated-Pd(Ⅱ) centers were determined. DMO was generated from the coupling of adjacent *COOCH;intermediates adsorbed on paired-Pd(Ⅱ) centers, while DMC was produced from the reaction between methyl nitrite and the *COOCH;intermediates formed on isolated-Pd(Ⅱ) centers. Current work is the first MOFs-based catalyst with well-defined structure being applied in CO oxidative coupling reaction, which not only sheds light on the structure-performance relationship, but also inspires the potential of using MOFs as tunable platform to design high-efficient catalysts in heterogeneous catalysis.
基金Projects(51774079,51674075)supported by the National Natural Science Foundation of ChinaProject(N182508026)supported by the Fundamental Research Funds for the Central Universities,China。
文摘The precipitation performance and kinetics of gibbsite from sodium aluminate solution with different sodium oxalate concentrations as well as the corresponding influence mechanism of oxalate during the seed precipitation process were systematically investigated by physicochemical properties test,using SEM and Raman spectra.As the concentration of sodium oxalate increases,both the precipitation rate and particle size of gibbsite decrease.The presence of sodium oxalate not only increases the viscosity of sodium aluminate solution,but also promotes the transformation of Al(OH)4^? to Al2O(OH)6^2?.The overall reaction rate constant decreases and the apparent activation energy of gibbsite increases with the increasing sodium oxalate concentration,the rate controlling step of which is chemical reaction.The needle-like sodium oxalate precipitates on the gibbsite crystals and covers the active Al(OH)3 seed sites,which leads to the lower precipitation rate and the finer particle size of gibbsite during the seed precipitation process.
