In the field of catalytic hydro-genation,two primary mecha-nistic pathways,namely the Ho-riuti-Polanyi(HP)mechanism and the non-HP mechanism,have been extensively investi-gated.Current understandings suggested that th...In the field of catalytic hydro-genation,two primary mecha-nistic pathways,namely the Ho-riuti-Polanyi(HP)mechanism and the non-HP mechanism,have been extensively investi-gated.Current understandings suggested that the non-HP mechanism preferred to occur on the coinage metal surfaces,such as copper,silver,and gold,which exhibited low activity towards H_(2) dissociation.Herein,we offered a detailed theoretical investigation into the mechanisms of CO_(2)hydrogenation to formic acid on M_(1)-In_(2)O_(3)(111)surfaces,using density functional theory calculations.Our calculations provided novel in-sights into the preference of the non-HP mechanism on reduced single-atom noble metal cata-lysts,such as r-Rh_(1)-In_(2)O_(3)(111)and r-Ir_(1)-In_(2)O_(3)(111).In these cases,molecularly adsorbed H_(2) would be polarized into H^(δ−)-H^(δ+),thus facilitating the electrophilic attack to the O in CO_(2).Conversely,the H^(δ+)species,derived from heterolytically dissociated H_(2),exhibited a strong affinity on the adjacent oxygen site at the M-O-In interface.This strong adsorption resulted in a higher energy barrier for CO_(2)hydrogenation,thereby rendering the HP mechanism less viable than the non-HP one.Our results were anticipated to provide a deeper understanding of hydrogenation reactions on oxide-supported noble single-atom catalysts and theoretical guidance for the development of novel high-performance catalysts for catalytic hydrogena-tion reactions.展开更多
基金supported by the National Key Research and Development Program of Ministry of Sci-ence and Technology of China(No.2022YFA1504601)the National Natural Science Foundation of China(Nos.92045303,22132004,22121001,22072116,22072117,and 21773192).
文摘In the field of catalytic hydro-genation,two primary mecha-nistic pathways,namely the Ho-riuti-Polanyi(HP)mechanism and the non-HP mechanism,have been extensively investi-gated.Current understandings suggested that the non-HP mechanism preferred to occur on the coinage metal surfaces,such as copper,silver,and gold,which exhibited low activity towards H_(2) dissociation.Herein,we offered a detailed theoretical investigation into the mechanisms of CO_(2)hydrogenation to formic acid on M_(1)-In_(2)O_(3)(111)surfaces,using density functional theory calculations.Our calculations provided novel in-sights into the preference of the non-HP mechanism on reduced single-atom noble metal cata-lysts,such as r-Rh_(1)-In_(2)O_(3)(111)and r-Ir_(1)-In_(2)O_(3)(111).In these cases,molecularly adsorbed H_(2) would be polarized into H^(δ−)-H^(δ+),thus facilitating the electrophilic attack to the O in CO_(2).Conversely,the H^(δ+)species,derived from heterolytically dissociated H_(2),exhibited a strong affinity on the adjacent oxygen site at the M-O-In interface.This strong adsorption resulted in a higher energy barrier for CO_(2)hydrogenation,thereby rendering the HP mechanism less viable than the non-HP one.Our results were anticipated to provide a deeper understanding of hydrogenation reactions on oxide-supported noble single-atom catalysts and theoretical guidance for the development of novel high-performance catalysts for catalytic hydrogena-tion reactions.
