Selective Oxidation of Hydrogen in the Presence of Propylene over Pt-Based Core–Shell Nanocatalysts

Abstract

Coupling of propane dehydrogenation with selective hydrogen oxidation is a practical strategy to achieve high propylene yield and low energy consumption. In this work, the detailed reaction mechanism on Pt(111) is explored using density functional theory calculations and microkinetic modeling to benefit the design of new catalysts. Calculated results indicate that the O2 dissociation pathway is dominant for hydrogen oxidation, and the dissociation of O2 is kinetically relevant. With the comparison between the energy barriers for dehydrogenation and oxidation, propyne is found to be the starting point for C3 oxidation. To obtain a high hydrogen oxidation rate and suppress the consumption of propylene, the catalytic performance of 11 M@Pt (M = Fe, Co, Ni, Cu, Ru, Rh, Os, Ir, Pd, Ag, and Au) core–shell surfaces is examined. Among all the core–shells, Ag@Pt not only has a high catalytic activity for hydrogen oxidation, but also exhibits a high selectivity toward propylene and is, therefore, the best candidate...