Magnetic-Field-Induced Strain Enhances Electrocatalysis of FeCo Alloys on Anode Catalysts for Water Splitting

Abstract

In water splitting, the oxygen evolution reaction (OER) performance of transition metal alloy catalysts needs to be further improved. To solve this problem, the method of an external magnetic field was used to improve the OER catalytic performance of the alloy catalyst. In this paper, FeCo alloys with different composition ratios were prepared by an arc melting method, and OER catalysts with different compositions were obtained by annealing treatment. Under the action of a magnetic field, all three groups of catalysts showed a better catalytic performance than those without a magnetic field. The overpotentials of Fe35Co65, Fe22Co78 and Fe15Co85 at a current density of 20 mA cm−2 were reduced by 12 mV, 6 mV and 2 mV, respectively. It is found that, due to the magnetostrictive properties of FeCo alloys, the catalyst itself will generate strain under the action of a magnetic field, and the existence of strain may be the main reason for the enhanced OER performance of the magnetic field. Therefore, this work provides a new idea for the development of magnetic material catalysts and a magnetic field to improve the performance of catalysts.

Recent advances in catalyst design and activity enhancement induced by a magnetic field for electrocatalysis

“…Strain may also be the mechanism of magnetic field enhancement. Liu 186 explored the change of the electrocatalytic performance of an FeCo alloy in the OER under a magnetic field and proposed that in the presence of a magnetic field, strain would occur in the FeCo alloy, leading to a significant reduction of OER overpotential. Although there have been scattered studies on the electron spin selectivity mechanism, mainly related to changes in the electron spin structure of the catalyst during catalysis, there is a need for in situ characterization of spintronic structures to better understand the theory and mechanism of spin catalysis.…”

Molecular Catalysts for OER/ORR in Zn–Air Batteries

“…Strain may also be the mechanism of magnetic field enhancement. Liu et al [117] explored the change of the electrocatalytic performance of an FeCo catalyst in the OER under a magnetic field and proposed that strain would occur in the FeCo alloy, reducing OER overpotential. In general, magnetic field-enhanced electrocatalysis has multiple mechanisms acting together.…”