Perspective-New Perspectives from Classical Transition State Theory: The Hydrogen Evolution Reaction on Metal Electrodes

New perspectives derive from classical transition state theory applied to hydrogen evolution reactions (HER). Trasatti found exchange current density j(0) increases exponentially with metal electrode work function F. The elementary electron transfer step M(e) + H-ads(+) reversible arrow M(0) + H-ads(center dot) specifies the metal in the transition state and derives rate equations where metal specific physiochemical property F is explicit. Linearity of log j(0) with Phi is quantified. Phi raises j(0) because Phi lowers the activation energy for electrocatalysis. Rate expressions that embed material specific physiochemical properties provide opportunities for a priori electrocatalyst design and fundamental insights on electron transfer kinetics. New perspectives derive from revisit of established HER data with classical transition state theory. (C) 2023 The Author(s). Published on behalf of The Electrochemical Society by IOP Publishing Limited. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 License (CC BY, http://creativecommons.org/licenses/ by/4.0/), which permits unrestricted reuse of the work in any medium, provided the original work is properly cited.