General principles for designing supported catalysts for hydrogen evolution reaction based on conceptual Kinetic Monte Carlo modeling

Abstract

Rational catalyst design presents one of the main paradigms in the contemporary materials science. Although the electronic structure calculations can be used to search for possible candidates, realistic supported catalysts are difficult to address in this way. In this contribution we use conceptual model of the supported hydrogen evolution reaction (HER) catalyst and investigate possible processes using Kinetic Monte Carlo simulations. In specific, we look at the possibility to boost H2 production by the H spillover to the support and the tailoring of the catalyst deposit. Different scenarios were considered depending on the nature of the HER rate determining step (RDS) on the catalyst surface and the effects of the rates of elementary processes, catalyst dispersion and morphology are analyzed. Metals with low affinity towards hydrogen should be used as catalyst supports, while H spillover can boost H2 production if Tafel or Heyrovsky reaction is the RDS on the catalyst surface. However, this can be achieved only if the catalyst dispersion is high, while the support has to act as a Hads acceptor and enable fast Hads recombination. General instructions for the choice of the catalyst|support combination can be used to design new advanced HER catalysts.