Development of a spin selective electrocatalyst platform and its use to study spin-polarization and d-orbital occupancy effects in oxygen evolution reaction electrocatalysts.

We describe a polymer-catalyst platform that uses spin-polarized electron currents, recently reported to improve the efficiency of the oxygen evolution reaction (OER), in combination with transition metal-oxide catalysts to enhance the efficiency of their OER electrocatalysis. We describe the creation of an electrode coated with a chiral conjugated polymer film which acts as a spin transport layer and ensures that anodic reaction proceeds with a spin bias. Systematic studies on a series of transition metal oxide catalysts demonstrate that spin selectivity improves catalytic efficiency irrespective of the catalysts position on a ‘volcano’ plot and that the benefit of electron spin filtering correlates with the number of unpaired d-orbital electrons in the catalyst. These studies identify spin-control as a design principle for engineering efficient OER catalysts. More broadly, these studies demonstrate a promising electrode scaffold for investigating the role of electron spin in chemical reactions.