Magnetocatalysis: The Interplay between the Magnetic Field and Electrocatalysis

Abstract

Magnetic fields are known as clean, economic, and effective tools to modify band and magnetic structures of materials. When coupled with catalytic processes such as hydrogen evolution reaction (HER), it has the potential to control the catalytic efficiencies. However, the underlying mechanism of magneto-catalysis is poorly studied and little understood. Here, we studied the magnetic response of a series of materials as HER catalysts, specifically, ferromagnetic Co 2 VGa, Co 2 MnGa and Ni, ferrimagnetic Mn 2 CoGa, and paramagnetic Pt.We found all the Heusler compounds exhibit impressively high intrinsic activities. Most importantly, the presence of a magnetic field could change the HER efficiencies significantly, regardless of the magnetic states of the catalysts. We observed boosting HER kinetics for ferromagnetic Ni and paramagnetic Pt, and a decrease of efficiency for ferro/ferrimagnetic Heusler alloys. Our calculations suggest that the binding energy between the reaction intermediate and the catalyst can be tailored effectively by controlling the number of transferred electrons. The findings highlight the vital role of magnetic fields in tailoring heterogeneous catalytic reactions that involving adsorption of reactants.

Review on Magnetism in Catalysis: From Theory to PEMFC Applications of 3d Metal Pt-Based Alloys

“…There are numerous examples in the literature showing that magnetic compositions containing Fe, Co and Ni exhibit outstanding catalytic performances when an external magnetic field is applied. Some of these examples are found in ORR [ 363 , 364 , 365 , 366 , 367 ], OER [ 368 , 369 , 370 ], HER [ 371 , 372 , 373 , 374 ] and water splitting reactions [ 288 ]. The same outcome is also observed in devices such as lithium-based batteries [ 362 , 375 , 376 ].…”

Recent Advances in External Fields‐Enhanced Electrocatalysis

“…Adapted with permission. [ 76 ] Copyright 2018, Springer Nature. b) Proposed three pathways of the OER influenced by magnetic fields and schematic illustration of the magnetic moment change of ferromagnetic materials.…”

“…Recently, Felser and co‐workers studied the magnetic response and HER behaviors of ferromagnetic Ni, paramagnetic Pt, and several Co‐based Heusler bulk crystals (Co 2 MnGa, Co 2 VGa, and Mn 2 CoGa). [ 76 ] The Heusler alloys exhibit high intrinsic activity for HER due to the high tunability of crystal symmetry and physical properties. However, the presence of magnetic field results in the inclusion of spin polarization and thus weaken the H 2 adsorption, decreasing the HER activity of Heusler alloys.…”

Electrochemistry in Magnetic Fields

“…So far, the spin modulation by the magnetic field has been applied to OER, [55][56][57]61] ORR, [61c, 62] HER, [63] CO 2 reduction reaction (CO 2 RR), [59] and oxalate oxidation reaction. [60] From our discussion, the spin-selective effect of ferromagnetic has been preliminarily shown as proof of concept.…”