Synthesis of N-propanol from CO2 Electroreduction on Bicontinuous Cu2O/Cu Nanodomains.

n-propanol is an important pharmaceutical and pesticide intermediate. To produce n-propanol by electrochemical reduction of CO2 is a promising way, but is largely restricted by the very low selectivity and activity. How to promote the coupling of *C1 and *C2 intermediates to form the *C3 intermediate for n-propanol formation is challenging. Here, we propose the construction of bicontinuous structure of Cu2O/Cu electrocatalyst, which consists of ultra-small Cu2O nanodomains, Cu nanodomains and large amounts of grain boundaries between Cu2O and Cu nanodomains. The n-propanol current density is as high as 101.6 mA cm-2 at the applied potential of -1.1 V vs. reversible hydrogen electrode in flow cell, with the Faradaic efficiency up to 12.1%. Moreover, the catalyst keeps relatively stable during electrochemical CO2 reduction process. Experimental studies and theoretical calculations reveal that the bicontinuous structure of Cu2O/Cu can facilitate the *CO formation, *CO-*CO coupling and *CO-*OCCO coupling for the final generation of n-propanol.

Alkaline Ionic Liquid Microphase Promotes Deep Reduction of CO2 on Copper.

Electrochemical reduction of CO2 to multicarbon (C2+) products using renewable energy sources is an important route to storing sustainable energy and achieving carbon neutrality. It remains a challenge to achieve high C2+ product faraday efficiency (FE) at ampere-level current densities. Herein, we propose the immobilization of an alkaline ionic liquid on copper for promoting the deep reduction of CO2. By this strategy, a C2+ FE of 81.4% can be achieved under a current density of 0.9 A·cm-2 with a half-cell energy conversion efficiency of 47.4% at -0.76 V vs reversible hydrogen electrode (RHE). Particularly, when the current density is as high as 1.8 A·cm-2, the C2+ FE reaches 71.6% at an applied potential of -1.31 V vs RHE. Mechanistic studies demonstrate that the alkaline ionic liquid plays multiple roles of improving the accumulation of CO2 molecules on the copper surface, promoting the activation of the adsorbed CO2, reducing the energy barrier of CO dimerization, stabilizing intermediates, and facilitating the C2+ product formation.

Cu/Cu2O nanocrystals for electrocatalytic carbon dioxide reduction to multi-carbon products.

We demonstrate the electrochemical conversion of carbon dioxide into multi-carbon products catalyzed by Cu/Cu2O nanocrystals, with a maximum C2+ faradaic efficiency of 75% in 0.10 M K2SO4 aqueous solution at -2.0 V versus Ag/AgCl and a partial current density of 34 mA cm-2.

Electrocatalytic Carbon Dioxide Reduction to Ethylene over Copper-based Catalytic Systems.

The electrocatalytic carbon dioxide (CO2 ) conversion to ethylene (C2 H4 ) has attracted significant attention in recent years. Copper-based catalytic systems have been proven to be the most efficient for producing C2 H4 from electrocatalytic CO2 reduction reaction. In this review, we present the recent progress on the electrocatalytic CO2 reduction to C2 H4 over copper-based catalytic systems, mainly focusing on reaction mechanism, design of catalysts and influences of electrolyte, CO2 supplement and electrolyzer on activity, selectivity and stability.