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
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.
