Ethylene(C_(2)H_(4))in vehicle exhaust is a highly reactive volatile organic compound(VOC).Its photooxidative reaction with NOx contributes to the formation of O3 and secondary organic aerosols(SOA),the latter being a...Ethylene(C_(2)H_(4))in vehicle exhaust is a highly reactive volatile organic compound(VOC).Its photooxidative reaction with NOx contributes to the formation of O3 and secondary organic aerosols(SOA),the latter being a key precursor of PM_(2.5).In this study,a novel MgO-supported Ag-Cu bimetallic catalyst was designed and investigated using density functional theory(DFT).The effects of Ag and Cu loading on the geometric structure,stability,and reactant adsorption characteristics of the catalyst were analyzed,and the catalytic oxidation pathways of C_(2)H_(4)over AgCu-MgO was elucidated.The results indicate that loading Ag significantly enhances the adsorption of C_(2)H_(4).The incorporation of Cu into Ag-MgO to form a AgCu-MgO bimetallic catalyst(dual atom catalyst,DACS)further improves the oxidative activity toward C_(2)H_(4).Based on the binding energies of the Ag and Cu bimetallic sites and the adsorption energies of C_(2)H_(4)and O_(2),three representative configurations were selected for detailed reaction pathway analysis.Among them,Configuration 6 of AgCu-MgO exhibited the highest catalytic oxidation performance.This study provides new atomic-scale insights for the rational design of efficient catalysts targeting olefinic pollutants in automotive emissions and offers valuable guidance for advancing exhaust after-treatment technologies.展开更多
Cu electrocatalysts have been demonstrated to have unique ability to reduce CO_(2)to various high value-added C_(2) products like ethylene and alcohols.However,realizing high selectivity of C_(2) products are still a ...Cu electrocatalysts have been demonstrated to have unique ability to reduce CO_(2)to various high value-added C_(2) products like ethylene and alcohols.However,realizing high selectivity of C_(2) products are still a main challenge due to complex CO_(2)electroreduction pathways and small opportunity of C-C coupling reactions.Here,we found the origin of enhanced CO_(2)electroreduction reaction activity and product selectivity towards C_(2) products and C-C coupling mechanism at halogen atoms-adsorbed Cu/H_(2)O interfaces,the corresponding CO_(2)electroreduction evolution mechanisms at the halogen atoms-modified Cu/H_(2)O interfaces are systematically studied via theoretical modeling and calculations.The calculated results indicate that halide anions modifications are beneficial to CO dimerization into OCCO dimer,especially Cl^(-)-adsorbed Cu(111)/H_(2)O interface has the optimum activity and selectivity towards OCCO dimer,subsequent Cl-adsorbed Cu(111)/H_(2)O interface can selectively reduce CO_(2)into C_(2)H_(4) product.The function relationship between adsorption free energy of Cl atom and electrode potential explain why the adsorption of Cl^(-)can enhance selectivity of C_(2)H_(4) product.The determinations of onset potentials indicate that electroreduction pathways of CO_(2)towards C_(2)H_(4) product are facile to take place and further explain the origin of the significantly enhanced CO production activity and C_(2)H_(4) product selectivity.This work on selective realization of CO_(2)electroreduction towards C_(2)H_(4) product via Cl^(-)-modified Cu(111)/H_(2)O interface provide a theoretical guideline for how to selectively realize other high value-added C_(2) products.展开更多
With increasing global energy demand and growing concerns over climate change,methods for catalytic reduction of CO_(2)have been extensively studied,among which graphitic carbon nitride(g-C_(3)N_(4))attracts remarkabl...With increasing global energy demand and growing concerns over climate change,methods for catalytic reduction of CO_(2)have been extensively studied,among which graphitic carbon nitride(g-C_(3)N_(4))attracts remarkable attention due to its easily available raw materials and outstanding chemical stability.However,its wide bandgap and low photon usage efficiency limit its application in photocatalysis.Doping g-C_(3)N_(4)to introduce active sites can enhance its catalytic performance.Herein,asymmetric phosphorus-cobalt dual sites were introduced onto g-C_(3)N_(4)via hydrothermal treatment and thermal polymerization.P(phosphorus)could enhance CO_(2)adsorption,while Co(cobalt)functions as a metallic site to boost the separation rate of photogenerated carriers.A photocatalytic CO_(2)reduction to CO with a rate of 93.2μmol/(g·h)was achieved,which was two times that of g-C_(3)N_(4).During stability testing,ethylene with a formation rate of approximately 2μmol/(g·h)was observed,as well as trace quantities of methanol and acetic acid in the liquid products.This work shows a promising strategy by the introduction of asymmetric phosphorous-cobalt dual sites for efficient photocatalytic conversion of CO_(2)to CO and C2 products.展开更多
Global investment in ethylene(C_(2)H_(4))production via nonpetroleum pathways is rising,highlighting its growing importance in the energy and environmental sectors.The electroreduction of carbon dioxide(CO_(2))to C_(2...Global investment in ethylene(C_(2)H_(4))production via nonpetroleum pathways is rising,highlighting its growing importance in the energy and environmental sectors.The electroreduction of carbon dioxide(CO_(2))to C_(2)H_(4) inflow cells is emerging as a promising technology with broad practical applications.Direct delivery of gaseous CO_(2) to the cathode catalyst layer overcomes mass transfer limitations,enhancing reaction rates and enabling high current density.This review summarizes recent research progress in the electrocatalytic CO_(2) reduction reaction(eCO_(2)RR)for selective C_(2)H_(4) production inflow cells.It outlines the principles of eCO_(2)RR to C_(2)H_(4) and discusses the influence of copper-based catalyst morphology,crystal facet,oxidation state,surface modification strategy,and synergistic effects on catalytic performance.In addition,it highlights the compositional structure of theflow cell,and the selection and optimization of operating conditions,including gas diffusion electrodes,electrolytes,ion exchange membranes,and alternative anode reaction types beyond the oxygen evolution reaction.Finally,advances in machine learning are presented for accelerating catalyst screening and predicting dynamic changes in catalysts during reduction.This comprehensive review serves as a valuable reference for the development of efficient catalysts and the construction of electrolytic devices for the electrocatalytic reduction of CO_(2) to C_(2)H_(4).展开更多
Photocatalytic reduction of CO_(2)into high-value C_(2)H_(4)offers a promising pathway toward carbon neutrality.Due to the continuous 12-electron-proton coupled reactions and the mutual repulsion of reaction intermedi...Photocatalytic reduction of CO_(2)into high-value C_(2)H_(4)offers a promising pathway toward carbon neutrality.Due to the continuous 12-electron-proton coupled reactions and the mutual repulsion of reaction intermediates,achieving highly selective photocatalytic conversion of CO_(2)to C_(2)H_(4)remains challenging.This work synthesized a CuInS_(2)/CuS heterojunction photocatalyst mediated by a sulfur electron bridge via a one-step solvothermal method,achieving a high selectivity for C_(2)H_(4)conversion(98.22%).The sulfur electron bridge minimized the contact energy barrier between CuInS_(2)and CuS to enhance photogenerated carrier separation efficiency,while the asymmetric active sites in CuInS_(2)effectively reduced mutual repulsion of reaction intermediates.This work develops a hybrid catalytic system enabling synergistic regulation of reaction kinetics and thermodynamics,offering an innovative strategy for highly selective photocatalytic CO₂-to-C_(2)H_(4)production.展开更多
Binary gas mixture adsorption equilibrium data for the ethylene-carbon dioxide system were obtained for cation exchanged forms of ZSM5 (Li^+, Na^+, K^+, Rb^+, Mg^(+2), Ca^(+2), Sr^(+2), and Ba^(+2)) for the gas phase ...Binary gas mixture adsorption equilibrium data for the ethylene-carbon dioxide system were obtained for cation exchanged forms of ZSM5 (Li^+, Na^+, K^+, Rb^+, Mg^(+2), Ca^(+2), Sr^(+2), and Ba^(+2)) for the gas phase CO_2 mole fracion of 0.766 at 308K and 101. 3kPa. The experimental adsorption phase diagrams were obtained for CO_2-C_2H_4 on NaZSM5 and MgZSM5. Single component adsorption isotherms for CO_2 and C_2H_4 were also obtained for these two zeolites. The single component data were used to obtain parameters derived in the vacancy solution model (VSM) and the statistical thermodynamic model(STM). These parameters were, in turn, used to predict binary mixture isotherms for these two zeolites. The agreement between experimental data and predicted value is generally good.展开更多
基金Supported by the National Natural Science Foundation of China Project(22362018)the Yunnan Fundamental Research Projects(202401AS070102)。
文摘Ethylene(C_(2)H_(4))in vehicle exhaust is a highly reactive volatile organic compound(VOC).Its photooxidative reaction with NOx contributes to the formation of O3 and secondary organic aerosols(SOA),the latter being a key precursor of PM_(2.5).In this study,a novel MgO-supported Ag-Cu bimetallic catalyst was designed and investigated using density functional theory(DFT).The effects of Ag and Cu loading on the geometric structure,stability,and reactant adsorption characteristics of the catalyst were analyzed,and the catalytic oxidation pathways of C_(2)H_(4)over AgCu-MgO was elucidated.The results indicate that loading Ag significantly enhances the adsorption of C_(2)H_(4).The incorporation of Cu into Ag-MgO to form a AgCu-MgO bimetallic catalyst(dual atom catalyst,DACS)further improves the oxidative activity toward C_(2)H_(4).Based on the binding energies of the Ag and Cu bimetallic sites and the adsorption energies of C_(2)H_(4)and O_(2),three representative configurations were selected for detailed reaction pathway analysis.Among them,Configuration 6 of AgCu-MgO exhibited the highest catalytic oxidation performance.This study provides new atomic-scale insights for the rational design of efficient catalysts targeting olefinic pollutants in automotive emissions and offers valuable guidance for advancing exhaust after-treatment technologies.
基金supported by the Natural Science Foundation of Hunan Province(No.2025JJ50059)Key Program of Hunan University of Arts and Science(No.23ZZ03)Aid Program for Science and Technology Innovative Research Team in Higher Educational Institutions of Hunan Province and National Natural Science Foundation of China(No.21303048).
文摘Cu electrocatalysts have been demonstrated to have unique ability to reduce CO_(2)to various high value-added C_(2) products like ethylene and alcohols.However,realizing high selectivity of C_(2) products are still a main challenge due to complex CO_(2)electroreduction pathways and small opportunity of C-C coupling reactions.Here,we found the origin of enhanced CO_(2)electroreduction reaction activity and product selectivity towards C_(2) products and C-C coupling mechanism at halogen atoms-adsorbed Cu/H_(2)O interfaces,the corresponding CO_(2)electroreduction evolution mechanisms at the halogen atoms-modified Cu/H_(2)O interfaces are systematically studied via theoretical modeling and calculations.The calculated results indicate that halide anions modifications are beneficial to CO dimerization into OCCO dimer,especially Cl^(-)-adsorbed Cu(111)/H_(2)O interface has the optimum activity and selectivity towards OCCO dimer,subsequent Cl-adsorbed Cu(111)/H_(2)O interface can selectively reduce CO_(2)into C_(2)H_(4) product.The function relationship between adsorption free energy of Cl atom and electrode potential explain why the adsorption of Cl^(-)can enhance selectivity of C_(2)H_(4) product.The determinations of onset potentials indicate that electroreduction pathways of CO_(2)towards C_(2)H_(4) product are facile to take place and further explain the origin of the significantly enhanced CO production activity and C_(2)H_(4) product selectivity.This work on selective realization of CO_(2)electroreduction towards C_(2)H_(4) product via Cl^(-)-modified Cu(111)/H_(2)O interface provide a theoretical guideline for how to selectively realize other high value-added C_(2) products.
基金supported financially by National Natural Science Foundation of China(No.52302226)the start-up Research Found of Southeast University(Nos.RF1028623127 and RF1028623128)the Natural Science Foundation of Jiangsu Province(No.BK20230812).
文摘With increasing global energy demand and growing concerns over climate change,methods for catalytic reduction of CO_(2)have been extensively studied,among which graphitic carbon nitride(g-C_(3)N_(4))attracts remarkable attention due to its easily available raw materials and outstanding chemical stability.However,its wide bandgap and low photon usage efficiency limit its application in photocatalysis.Doping g-C_(3)N_(4)to introduce active sites can enhance its catalytic performance.Herein,asymmetric phosphorus-cobalt dual sites were introduced onto g-C_(3)N_(4)via hydrothermal treatment and thermal polymerization.P(phosphorus)could enhance CO_(2)adsorption,while Co(cobalt)functions as a metallic site to boost the separation rate of photogenerated carriers.A photocatalytic CO_(2)reduction to CO with a rate of 93.2μmol/(g·h)was achieved,which was two times that of g-C_(3)N_(4).During stability testing,ethylene with a formation rate of approximately 2μmol/(g·h)was observed,as well as trace quantities of methanol and acetic acid in the liquid products.This work shows a promising strategy by the introduction of asymmetric phosphorous-cobalt dual sites for efficient photocatalytic conversion of CO_(2)to CO and C2 products.
基金supported by the National Natural Science Foundation of China(22272081 and 51802160)the Startup Foundation for Introducing Talent of NUIST(S8113082001).
文摘Global investment in ethylene(C_(2)H_(4))production via nonpetroleum pathways is rising,highlighting its growing importance in the energy and environmental sectors.The electroreduction of carbon dioxide(CO_(2))to C_(2)H_(4) inflow cells is emerging as a promising technology with broad practical applications.Direct delivery of gaseous CO_(2) to the cathode catalyst layer overcomes mass transfer limitations,enhancing reaction rates and enabling high current density.This review summarizes recent research progress in the electrocatalytic CO_(2) reduction reaction(eCO_(2)RR)for selective C_(2)H_(4) production inflow cells.It outlines the principles of eCO_(2)RR to C_(2)H_(4) and discusses the influence of copper-based catalyst morphology,crystal facet,oxidation state,surface modification strategy,and synergistic effects on catalytic performance.In addition,it highlights the compositional structure of theflow cell,and the selection and optimization of operating conditions,including gas diffusion electrodes,electrolytes,ion exchange membranes,and alternative anode reaction types beyond the oxygen evolution reaction.Finally,advances in machine learning are presented for accelerating catalyst screening and predicting dynamic changes in catalysts during reduction.This comprehensive review serves as a valuable reference for the development of efficient catalysts and the construction of electrolytic devices for the electrocatalytic reduction of CO_(2) to C_(2)H_(4).
文摘Photocatalytic reduction of CO_(2)into high-value C_(2)H_(4)offers a promising pathway toward carbon neutrality.Due to the continuous 12-electron-proton coupled reactions and the mutual repulsion of reaction intermediates,achieving highly selective photocatalytic conversion of CO_(2)to C_(2)H_(4)remains challenging.This work synthesized a CuInS_(2)/CuS heterojunction photocatalyst mediated by a sulfur electron bridge via a one-step solvothermal method,achieving a high selectivity for C_(2)H_(4)conversion(98.22%).The sulfur electron bridge minimized the contact energy barrier between CuInS_(2)and CuS to enhance photogenerated carrier separation efficiency,while the asymmetric active sites in CuInS_(2)effectively reduced mutual repulsion of reaction intermediates.This work develops a hybrid catalytic system enabling synergistic regulation of reaction kinetics and thermodynamics,offering an innovative strategy for highly selective photocatalytic CO₂-to-C_(2)H_(4)production.
文摘Binary gas mixture adsorption equilibrium data for the ethylene-carbon dioxide system were obtained for cation exchanged forms of ZSM5 (Li^+, Na^+, K^+, Rb^+, Mg^(+2), Ca^(+2), Sr^(+2), and Ba^(+2)) for the gas phase CO_2 mole fracion of 0.766 at 308K and 101. 3kPa. The experimental adsorption phase diagrams were obtained for CO_2-C_2H_4 on NaZSM5 and MgZSM5. Single component adsorption isotherms for CO_2 and C_2H_4 were also obtained for these two zeolites. The single component data were used to obtain parameters derived in the vacancy solution model (VSM) and the statistical thermodynamic model(STM). These parameters were, in turn, used to predict binary mixture isotherms for these two zeolites. The agreement between experimental data and predicted value is generally good.
