Tailoring the Activity of Electrocatalytic Methanol Oxidation on Cobalt Hydroxide by the Incorporation of Catalytically Inactive Zinc Ions

Catalytically inactive Zn2+ is incorporated into cobalt hydroxide to synthesize hierarchical ZnCo-layered double hydroxide nanosheet networks supported on carbon fiber (ZnCo-LDH/CF). The incorporation of Zn2+ is revealed to endow ZnCo-LDH/CF with significantly superior performance in the aspects of the activity and selectivity for methanol electrooxidation to formic acid and the boosting effect for cathodic hydrogen production compared with the counterpart without Zn2+. Density functional theory (DFT) calculation reveals that the incorporation of nonactive Zn2+ can increase the density of states near the Fermi level of LDH (i.e., elevate electrical conductivity to form favorable charge transportation during electrocatalysis) and promote the adsorption and subsequent cleavage of methanol, thus leading to the enhanced methanol electrooxidation performance.