Platinum-Based Electrocatalysts for the Oxygen-Reduction Reaction: Determining the Role of Pure Electronic Charge Transfer in Electrocatalysis

摘要

In the oxygen-reduction reaction (ORR), electronic charge transfer (ECT) derived from alloy components and support materials generates noticeable impact on the electrocatalytic activity of Pt. However, generally, ECT will not individually occur; thus, its role remains controversial. Here, using different amount of Au to decorate Pt nanoparticles, ECT from Au to Pt is isolated to correlate with the ORR activity of Pt. The linear correlation, where pure ECT (assessed by Pt 5d orbital vacancy) depresses the adsorption of oxygenated species to enhance the ORR activity, predicts that the maximum activity enhancement should be smaller than 200%. These findings highlight that the ECT effect in the ORR is weaker than the previously reported size, facet, or strain effects, which establishes a basis for understanding exceptional ORR electrocatalysis and developing efficient Pt-based electrocatalysts.