Selective Dissociation of Dihydrogen over Dioxygen on a Hindered Platinum Surface for the Direct Synthesis of Hydrogen Peroxide

Abstract

Abstract To achieve high catalytic selectivity towards H 2 O 2 from a H 2 /O 2 mixture, HH bonds should be dissociated and OO bonds should be kept intact in the course of the reaction. A major dilemma in catalyst design, however, is that the metal catalysts that dissociate HH bonds have a thermodynamic preference for the dissociation of OO bonds. In this work, the selective dissociation of H 2 over O 2 was realized by the deposition of H 2 ‐selective carbon diffusion layers on a Pt catalyst. Because O 2 cannot access the carbon‐coated Pt surface, O 2 hydrogenation occurs at the carbon surface from spilt‐over hydrogen rather than at the Pt surface on which OO dissociation is likely. This leads to the great suppression of OO dissociation, which allows the highly selective synthesis of H 2 O 2 . Notably, N‐doping of the carbon diffusion layer could increase the selectivity towards H 2 O 2 significantly because of the stabilization of the hydroperoxy radical on the carbon surface.