标题：Direct Identification of Active Surface Species for the Water-Gas Shift Reaction on a Gold-Ceria Catalyst
作者：Fu, Xin-Pu; Gno, Li-Wen; Wang, Wei-Wei; Ma, Chao; Jia, Chun-Jiang; Wu, Ke; Si, Rui; Sun, Ling-Dong; Yan, Chun-Hua
作者机构：[Fu, Xin-Pu; Gno, Li-Wen; Wang, Wei-Wei; Jia, Chun-Jiang] Shandong Univ, Sch Chem & Chem Engn, Key Lab Special Aggregated Mat, Key Lab Colloid & Inter 更多
通讯作者：Jia, ChunJiang;Jia, CJ;Si, R;Yan, CH
通讯作者地址：[Jia, CJ]Shandong Univ, Sch Chem & Chem Engn, Key Lab Special Aggregated Mat, Key Lab Colloid & Interface Chem, Jinan 250100, Shandong, Peoples R Chin 更多
来源：JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
摘要：The crucial role of the metal-oxide interface in the catalysts of the water-gas shift (WGS) reaction has been recognized, while the precise illustration of the intrinsic reaction at the interfacial site has scarcely been presented. Here, two kinds of gold-ceria catalysts with totally distinct gold species, <2 nm clusters and 3 to 4 nm particles, were synthesized as catalysts for the WGS reaction. We found that the gold cluster catalyst exhibited a superiority in reactivity compared to gold nanoparticles. With the aid of comprehensive in situ characterization techniques, the bridged -OH groups that formed on the surface oxygen vacancies of the ceria support are directly determined to be the sole active configuration among various surface hydroxyls in the gold-ceria catalysts. The isotopic tracing results further proved that the reaction between bridged surface -OH groups and CO molecules adsorbed on interfacial Au atoms contributes dominantly to the WGS reactivity. Thus, the abundant interfacial sites in gold clusters on the ceria surface induced superior reactivity compared to that of supported gold nanoparticles in catalyzing the WGS reaction. On the basis of direct and solid experimental evidence, we have obtained a very clear image of the surface reaction for the WGS reaction catalyzed by the gold-ceria catalyst.