Harnessing magnetic fields: temporal-spatial enabling in water-splitting electrocatalysis

Abstract

While the catalytic enhancement effect of magnetic fields in electrocatalytic water splitting has been established, the underlying mechanisms and optimal application strategies remain poorly understood. Here, we present a comprehensive investigation of the effects of a magnetic field on electrocatalysis using engineered Co-Ru@RuO2 ferrimagnetic materials, elucidating the complex relationships among magnetic fields, spin coupling, and catalytic activity in both oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER). Our systematic study reveals a threshold-dependent response: weak magnetic fields (<1 T) have a negligible impact under electrochemical steady-state conditions, whereas strong magnetic fields (>3 T) significantly alter the steady state and enhance the catalytic performance. We introduce the novel concept of temporal-spatial enabling, demonstrating that the precisely timed application of magnetic fields particularly prior to electrochemical reactions can significantly enhance catalytic efficiency in both the OER and HER. Through innovative quasi-in situ temperature-dependent magnetization measurements, we provide direct evidence that magnetic fields modulate the electronic spin structure of the catalyst, resulting in improved catalytic activity. These findings not only deepen our fundamental understanding of magnetic field effects in electrocatalysis but also establish a new paradigm for optimizing catalytic performance via strategic manipulation of magnetic fields and spin dynamics, opening promising avenues for next-generation energy conversion technologies.