The modulating mechanism of the second metal in bimetallic catalysts for the catalytic properties has always been a hot topic.Pd13−mAgm(m=0–13)clusters are used as the model catalysts to explore the influence of Ag-i...The modulating mechanism of the second metal in bimetallic catalysts for the catalytic properties has always been a hot topic.Pd13−mAgm(m=0–13)clusters are used as the model catalysts to explore the influence of Ag-induced configurational and electronic evolution of the PdAg phase on the catalytic performance of acetylene semi-hydrogenation by theoretical calculations.From the results obtained,it can be found that the activity/selectivity to ethylene dramatically depends on the geometric and electronic structures of 13-atom bimetallic clusters in the subnanometer size regime.The adsorption configuration of the C_(2) species is determined by the structure of bimetallic clusters,which can be attributed to the reasonable matching with the highest occupied molecular orbital(HOMO).A metastable composition Pd6Ag7 cluster,exhibiting the biggest difference in electrons supplied from the clusters to acetylene and ethylene,promotes the reaction path of the target product in the semi-hydrogenation of acetylene.The modulating mechanism of silver has been deeply explored in this paper,which will provide important theoretical guidance for the rational design and development of bimetallic catalysts.展开更多
基金supported by the National Natural Science Foundation of China(U1908203)the Natural Science Foundation of Liaoning Province(2020-MS-284).
文摘The modulating mechanism of the second metal in bimetallic catalysts for the catalytic properties has always been a hot topic.Pd13−mAgm(m=0–13)clusters are used as the model catalysts to explore the influence of Ag-induced configurational and electronic evolution of the PdAg phase on the catalytic performance of acetylene semi-hydrogenation by theoretical calculations.From the results obtained,it can be found that the activity/selectivity to ethylene dramatically depends on the geometric and electronic structures of 13-atom bimetallic clusters in the subnanometer size regime.The adsorption configuration of the C_(2) species is determined by the structure of bimetallic clusters,which can be attributed to the reasonable matching with the highest occupied molecular orbital(HOMO).A metastable composition Pd6Ag7 cluster,exhibiting the biggest difference in electrons supplied from the clusters to acetylene and ethylene,promotes the reaction path of the target product in the semi-hydrogenation of acetylene.The modulating mechanism of silver has been deeply explored in this paper,which will provide important theoretical guidance for the rational design and development of bimetallic catalysts.
