REDEEM-electrocat: Rethinking Electrode Design - Emergent Electronic and Magnetic effects in electrocatalysis

Lead Research Organisation: Science and Technology Facilities Council
Department Name: Scientific Computing Department

Abstract

Electrocatalysis (EC) lies at the heart of most of the emerging technologies for a sustainable future. Enormous efforts are being directed towards designing and modifying catalysts for a range of reactions relevant to fuel generation and use, energy storage, and bulk chemical production. Within EC, and the wider field of heterogeneous catalysis, catalysts achieve changes in rate, and hence selectivity, of a particular pathway through modification of the energy of adsorbed intermediates and transition states (TS) of the elementary steps along a reaction pathway.

Unfortunately, binding energies of intermediates and TS are usually strongly correlated. As a result, modifications in the structure or composition of the catalysts are often ineffective in breaking these correlations (scaling relationships). Reactive surfaces that bind an initial state more strongly often also bind the TS and final state more strongly too, leading to minimal change in the energy-barrier (rate) of the step.

Scaling relationships have been long known in catalysis but research in new strategies to deliberately circumvent them is far newer. Approaches are emerging in EC such as the isolated or combined use of strained structures, high dilution alloys, and ligand modified surfaces. These require a fundamental redesign of the catalysts. Currently overlooked is the potential of in-situ generated magnetic fields to break scaling relationships for intermediates and transition states with different spin-multiplicity, which are inevitably present in multi-electron processes.

This proposal aims to explore the potential of established solutions in spintronics to generate local magnetic fields for breaking scaling relationships in EC.

Publications

10 25 50
 
Description New electrode structures which generate out of plane magnetic fields and possible spin polarisation of the current have been prepared and tested for three model reactions. Studies on carbon dioxide reduction indicate that the magnetic field may inhibit activity. Studies on water oxidation show an increase in activity with gold electrodes, traditionally a less active surface. Hydrogen evolution can be supressed in acid but enhanced in alkali due to an interplay of spin and magnetic effects. Overall we believe we have demonstrated that we can decouple spin-state control from magnetic field effects during electrocatalysis. A manuscript is in preparation as is a patent filing
Exploitation Route Contact industry for potential commercial development -but first further research is needed to confirm the findings and see potential for scaling etc.
Sectors Energy,Environment