Spin effects in electrocatalysis: Mechanisms, catalyst engineering, modulation, and applications

Abstract

Catalytic reactions are often governed by the fundamental parameter of spin, making the modulation of electron spin the key to overcoming the limitations of reaction efficiency. Despite advances, the relationship between spin effects and electrocatalytic properties remains not fully understood. This review explores the impact of electronic spin on key reaction intermediates and metal active sites in electrocatalytic reactions, with a particular focus on the role of spin effects in catalytic mechanisms. The electronic spin effects, including double-exchange, super-exchange, spin polarization, chirality-induced spin selectivity, and spin-orbit coupling effects, are first introduced to clarify their effects on intermediates, electron transfer and orbital interactions in electrocatalytic reactions. The fundamental characteristics and mechanisms of several typical electrocatalytic reactions are then summarized, with particular emphasis on the critical role of spin effects in adsorption and desorption behavior of reaction intermediates, followed by a more in-depth discussion of examples of spin catalysts in optimizing both reaction kinetics and thermodynamics. Moreover, spin engineering strategies, such as doping, strain, interface engineering, and external magnetic field-assisted approaches, that serve to modify the spin configuration of active sites and the adsorption strength of intermediates, thereby influencing spin-selective electron transfer during reactions, are reviewed in detail. Finally, this review examines the prospects of spin in various catalytic processes, emphasizing the importance of spin effects in enhancing catalytic efficiency, reaction kinetics, and thermodynamic performance. It also explores the challenges and opportunities that future research may encounter.