Active Site Customizing of Metal–Organic Materials for Highly Efficient Oxygen Evolution

Abstract

Elucidating the correlation of active sites and catalytic activity in multi‐component metal–organic frameworks (MOFs) is key to understanding the mechanism of oxygen evolution reaction (OER), yet it remains nebulous. Herein, a direct pathway combining theoretical prediction with anchoring high‐valence metals is proposed on MOFs to reveal the mechanism of the OER reaction. Density functional theory (DFT) predicts that the co‐modulation by Mo and Co atoms can enhance the conductance of CoMOF and optimize the adsorption‐free energies of the OER intermediates. Guided by the theoretical prediction, the Co‐based MOFs grown on Ni foams are doped with high valence Mo, which is used as model catalysts for the quantitative study of the composition‐dependent OER performance. With Co/Mo in the ratio of 5:1 for the highest OER activity (impressively overpotential of 324 mV at 100 mA cm−2 and a Tafel slope of 96.07 mV dec−1) and excellent stability (maintains for 200 h at 100 mA cm−2), the catalysts in this work is superior to commercial benchmarks electrocatalysts (RuO2/NF, 420 mV, 199.12 mV dec−1). This work sheds light on the tailoring of the active sites of MOFs, which is highly correlated with the activity of the OER.