A synergistic charge-transfer mechanism to improve the electrocatalytic oxygen evolution reaction on a novel Pt-MOF composite

A novel composite Pt-MOF was fabricated by mixing 50 wt% of Pt nanoparticles supported on Vulcan carbon and 50 wt% of a cobalt-based MOF, LEEL-037 (1,2-di(4-pyridyl)ethylene, 1,2,4,5-benzene tetracarboxylic acid, and cobalt). As a result of an increment in the OH − adsorption rate on the composite's surface, LEEL-037/Pt–C showed enhanced electrochemical activity to perform the oxygen evolution reaction (OER) compared to bare materials. The improved OH − adsorption is attributed to an electron transference from the pyridine group on LEEL-037 to Pt nanoparticles, which generates a low electronic density region on the LEEL-037 surface; thus, presenting a high affinity to adsorb OH − anions, which is the key step prior the OER in alkaline media. Graphic abstract