Tandem Catalytic Electro-Reduction of Carbon Dioxide into Ethylene at Industrial Scale

Abstract

The electrochemical reduction of CO2 into value-added multi-carbon products, for example C2H4, with efficiency and production rate at industrial level requires innovation of new catalyst concepts. Researchers have screened a wide range of metal-based materials for electrochemical reduction of CO2, and found only copper-based metals exhibit selectivity towards formation of hydrocarbons and oxygenates at fairly high efficiencies while silver and gold favor production of carbon monoxide (CO). In addition, recent studies have discovered that copper can catalyze CO electro-reduction at lower overpotentials, higher selectivity towards C2 products and higher production rate than CO2 electro-reduction. This phenomenon provides an opportunity to design cascade reaction through CO intermediate to improve the yield of C2 products from direct CO2 electro-reduction. Here we introduce the development of our tandem catalysis system involving both CO- and C2-selective catalysts to drive electro-reduction of CO2 into high order hydrocarbon products with a yield at industrial scale. The overall Faradaic efficiency of C2 products could be achieved up to 90% and the current density was reached over 1 A cm-2 at cathodic overpotentials of around -0.5 V. The cathodic CO2 electro-reduction can combine with anodic biomass valorization to offer more economic feasibility. Our study brings CO2 electro-reduction technology one step forward towards the industrial application.