Enhanced Carbon Monoxide Electroreduction to >1 A cm -2 C 2+ Products Using Copper Catalysts Dispersed on MgAl Layered Double Hydroxide Nanosheet House-of-Cards Scaffolds.

Cu catalysts are most apt for reducing CO (2) to multi-carbon products in aqueous electrolytes. To enhance the product yield, we can increase the overpotential and the catalyst mass loading. However, these approaches can cause inadequate mass transport of CO (2) to the catalytic sites, which will then lead to H 2 evolution dominating the product selectivity. Herein, we use a MgAl LDH nanosheet 'house-of-cards' scaffold to disperse CuO-derived Cu (OD-Cu). With this support-catalyst design, at -0.7 V RHE , CO could be reduced to C 2+ products with a current density (j C2+ ) of -1251 mA cm -2 . This is 14× that of the j C2+ shown by unsupported OD-Cu. The current densities of C 2+ alcohols and C 2 H 4 were also high at -369 and -816 mA cm -2 respectively. We propose that the porosity of the LDH nanosheet scaffold enhances CO diffusion through the Cu sites. The CO reduction rate can thus be increased, while minimizing H 2 evolution, even when high catalyst loadings and large overpotentials are used.