Dynamic Promotion of the Oxygen Evolution Reaction via Programmable Metal Oxides

Abstract

Hydrogen gas is a promising renewable energy storage medium when produced via water electrolysis, but this process is limited by the sluggish kinetics of the anodic oxygen evolution reaction (OER). Herein, we used a microkinetic model to investigate promoting the OER using programmable oxide catalysts (i.e., forced catalyst dynamics). We found that programmable catalysts could increase current density at a fixed overpotential (100−600× over static rates) or reduce the overpotential required to reach a fixed current density of 10 mA cm −2 (45−140% reduction vs static). In our kinetic parametrization, the key parameters controlling the quality of the catalytic ratchet were the O*-to-OOH* and O*-to-OH* activation barriers. Our findings indicate that programmable catalysts may be a viable strategy for accelerating the OER or enabling lower-overpotential operation, but a more accurate kinetic parametrization is required for precise predictions of performance, ratchet quality, and resulting energy efficiency.

Cyclic Steady-State Simulation and Waveform Design for Dynamic/Programmable Catalysis

“…In this subsection, we describe two different approaches for the simulation of dynamic catalytic systems, so-called sequential and simultaneous. The former approach consists in simulating the systems from the start of the reactive process until CSS is achieved, and it is commonly used in the literature. − ,,, The latter provides solutions directly for CSS and is the main method discussed in this work.…”

“…Rate enhancement and computational analysis of oscillation parameters were also applied to more realistic systems: formic acid electro-oxidation over Pt; ammonia synthesis on Ru under applied surface strain and different active site types; electrocatalytic oxygen evolution reaction over metal oxides, with fixed overpotential and an additional arbitrary stimulus source; and methane steaming reform under Ru(211) subject to applied charge …”