Metal Support Interaction in Pt Nanoparticles Partially Confined in the Mesopores of Microsized Mesoporous CeO₂ for Highly Efficient Purification of Volatile Organic Compounds

The Pt/CeO 2 nanocomposites of Pt nanoparticles partially confined in the mesopores of microsized mesoporous CeO 2 (1.0% Pt/CeO 2 -MM) or supported on the surface of CeO 2 nanocubes (1.0% Pt/CeO 2 -NC) with the same Pt loading of 1.0 wt % were prepared by the impregnation of microsized mesoporous CeO 2 or CeO 2 nanocubes with Pt(NO 3 ) 2 aqueous solution, followed by the reduction with NaBH 4 aqueous solution. 1.0%Pt/CeO 2 -MM exhibits much higher catalytic activity for benzene oxidation than 1.0%Pt/CeO 2 -NC. Compared to 1.0% Pt/CeO 2 -NC, the reaction temperatures of T 50 and T 90 (corresponding to a benzene conversion = 50% and 90%) for 1.0% Pt/CeO 2 -MM tremendously decreases by Δ T 50 = 149 °C and Δ T 90 = 196 °C, respectively. The turnover frequency (TOF) of 1.0% Pt/CeO 2 -MM at 140 °C increases by 9.0 times as compared to that of 1.0% Pt/CeO 2 -NC. The tremendous enhancement in the catalytic activity is due to a novel metal support interaction in 1.0% Pt/CeO 2 -MM. The novel metal support interaction is theoretically studied by density function theory (DFT) calculation and experimentally studied by CO-TPR, CO-TPD, H 2 pulse titration, and HRTEM. The theoretical and experimental evidence reveal that the partial confinement of Pt nanoparticles in the mesopores of microsized mesoporous CeO 2 leads to a significant enhancement in the activity of the surface lattice oxygen around the interface between Pt nanoparticles and CeO 2, thus tremendously increasing the catalytic activity.