The direct synthesis of hydrogen peroxide from H 2 and O 2 using Pd–Ni/TiO 2 catalysts

Abstract

The direct synthesis of hydrogen peroxide (H 2 O 2 ) from molecular H 2 and O 2 offers an attractive, decentralized alternative to production compared to the current means of production, the anthraquinone process. Herein we evaluate the performance of a 0.5%Pd–4.5%Ni/TiO 2 catalyst in batch and flow reactor systems using water as a solvent at ambient temperature. These reaction conditions are considered challenging for the synthesis of high H 2 O 2 concentrations, with the use of sub-ambient temperatures and alcohol co-solvents typical. Catalytic activity was observed to be stable to prolonged use in multiple batch experiments or in a flow system, with selectivities towards H 2 O 2 of 97% and 85%, respectively. This study was carried out in the absence of halide or acid additives that are typically used to inhibit sequential H 2 O 2 degradation reactions showing that this Pd–Ni catalyst has the potential to produce H 2 O 2 selectively. This article is part of a discussion meeting issue ‘Science to enable the circular economy’.