Ordered Mesopore Confined Pt Nanoclusters Enable Unusual Self-Enhancing Catalysis

As an important kind of emerging heterogeneous catalyst for sustainable chemical processes, supported metal cluster (SMC) catalysts have received great attention for their outstanding activity; however, the easy aggregation of metal clusters due to their migration along the substrate's surface usually deteriorates their activity and even causes catalyst failure during cycling. Herein, stable Pt nanoclusters (NCs, similar to 1.06 nm) are homogeneously confined in the uniform spherical mesopores of mesoporous titania (mpTiO(2)) by the interaction between Pt NCs and metal oxide pore walls made of polycrystalline anatase TiO2. The obtained Pt-mpTiO(2) exhibits excellent stability with well-retained CO conversion (similar to 95.0%) and Pt NCs (similar to 1.20 nm) in the long term water-gas shift (WGS) reaction. More importantly, the Pt-mpTiO(2) displays an unusual increasing activity during the cyclic catalyzing WGS reaction, which was found to stem from the in situ generation of interfacial active sites (Ti3+-O-v-Pt delta+) by the reduction effect of spillover hydrogen generated at the stably supported Pt NCs. The Pt-mpTiO(2) catalysts also show superior performance toward the selective hydrogenation of furfural to 2-methylfuran. This work discloses an efficient and robust Pt-mpTiO(2) catalyst and systematically elucidates the mechanism underlying its unique catalytic activity, which helps to design stable SMC catalysts with self-enhancing interfacial activity in sustainable heterogeneous catalysis.