Efficient Noble Metal-Free (Electro)Catalysis of Water and Alcohol Oxidations by Zinc–Cobalt Layered Double Hydroxide

Abstract

Replacing rare and expensive noble metal catalysts with inexpensive and earth-abundant ones for various renewable energy-related chemical processes as well as for production of high value chemicals is one of the major goals of sustainable chemistry. Herein we show that a bimetallic Zn-Co layered double hydroxide (Zn-Co-LDH) can serve as an efficient electrocatalyst and catalyst for water and alcohol oxidation, respectively. In the electrochemical water oxidation, the material exhibits a lower overpotential, by ~100 mV, than monometallic Co-based solid-state materials (e.g., Co(OH)2 and Co3O4)-catalytic systems that were recently reported to be effective for this reaction. Moreover, the material's turnover frequency (TOF) per Co atoms is >10 times as high as those of the latter at the same applied potentials. The Zn-Co-LDH also catalyzes oxidation of alcohols to the corresponding aldehydes or ketones at relatively low temperature, with moderate to high conversion and excellent selectivity.