Amino Assisted Protonation for Carbon−Carbon Coupling During Electroreduction of Carbon Dioxide to Ethylene on Copper(I) Oxide

Abstract

The development of effective catalysts for the electrocatalytic carbon dioxide reduction reaction (CO 2 RR) to two-carbon (C 2 ) products is a practical approach to solve the energy crisis and stabilize the carbon cycle of the ecosystem. The production of electrocatalytic CO 2 RR with copper metal shows low selectivity and mainly generates one-carbon (C 1 ) products, hindering its wide practical application. The use of copper (I) oxide (Cu 2 O) in electrocatalysis has attracted intense research attention because it can more efficiently produce C 2 products with high energy density such as ethylene (C 2 H 4 ) and ethane (C 2 H 6 ). We use an amino-modified Cu 2 O catalyst (NH 2 À Cu 2 O) for electrocatalytic CO 2 RR to obtain significantly increased production of the CO and C 2 products. Electrochemical in-situ infrared spectroscopy analysis was used to detect the presence of the *COOH and *CHO reaction intermediates. Density functional theory calculations showed that the amino (À NH 2 ) modification reduces the free energy of the *CO!*CHO reaction that is the ratedetermining step in C 2 H 4 production. Our results show that amino modification can promote the protonation of *CO and *CHO carbon-carbon coupling to produce C 2 H 4 . Thus, aminomodified copper-based catalysts are promising materials for application in electrocatalytic CO 2 RR to multi-carbon products.

Self-Assembled Co3O4 Nanospheres on N-Doped Reduced Graphene Oxide (Co3O4/N-RGO) Bifunctional Electrocatalysts for Cathodic Reduction of CO2 and Anodic Oxidation of Organic Pollutants

“…6,7 Demanding the production-specific fuel-grade compound, ECR CO 2 can be adjusted by the electrocatalytic conditions of electrolytes, applied potential, and different electrode materials. 3,8,9 To achieve efficient ECR CO 2 , various high-performance electrocatalysts have been reported in the literature. 10,11 Early studies have reported that CO has formed on Zn, Ag, and Au electrodes with a potential range of −0.45−−0.9 V RHE , while Bi, Sn, Pb, S doped Cu, Cu 3 Sn, Cu/Au, and Cd electrodes are potentially involved in converting CO 2 to formic acid at of 0.05−−0.25 V RHE .…”

“…Many research groups have focused on capturing and utilizing CO 2 to mitigate global warming and climate changes, which can enable the sustainable production of various liquid chemicals and fuels. , Several catalytic conversion technologies have attempted to convert CO 2 into value-added chemicals such as CH 3 OH, CH 3 CH 2 OH, CO, formic acid, CH 4 , and so forth . , Electrochemical CO 2 reduction (ECR CO 2 ) offers an attractive technology for converting flue gases into selective production of liquid fuels under mild operating conditions. , Demanding the production-specific fuel-grade compound, ECR CO 2 can be adjusted by the electrocatalytic conditions of electrolytes, applied potential, and different electrode materials. ,, To achieve efficient ECR CO 2 , various high-performance electrocatalysts have been reported in the literature. , Early studies have reported that CO has formed on Zn, Ag, and Au electrodes with a potential range of −0.45––0.9 V RHE , while Bi, Sn, Pb, S doped Cu, Cu 3 Sn, Cu/Au, and Cd electrodes are potentially involved in converting CO 2 to formic acid at of 0.05––0.25 V RHE . , Furthermore, Pt, Ni, Fe, and their nanocomposites-based hybrid electrodes are H 2 -selective materials with a potential of −0.25––0.45 V RHE , while the material classes such as carbides, sulfides, oxides, and their carbon-based electrodes possessed a selective production of alcohols such as CH 3 OH, CH 3 CH 2 OH, at a potential of −0.3––0.75 V RHE . , Of particular interest is the development of low-cost, efficient, and key functional electrodes for the selective production of CH 3 OH . Recent studies of RuO 2 , RuO 2 /TiO 2 , W/Au alloy, FeS 2 /NiS, cobalt/N-graphene, MoS 2 /Bi 2 S 3 , Cu 2– x Se­( y ) nanocatalysts, and multicomponent mixtures have been studied for the selective formation of CH 3 OH in alkaline solutions. ,− In spite of these developments, many challenges remain in the development of bifunctional electrocatalysts for increasing the production rate of CH 3 OH under mild reaction conditions .…”

Surface Modification of Nano‐Cu2O for Controlling CO2 Electrochemical Reduction to Ethylene and Syngas

“…However, for the decomposition of *COOH intermediate into H 2 O molecule and *CO intermediate, the free energy on Cu 2 O (332) is higher than that on Cu 2 O (111) and Cu 2 O (100), indicating that the hydrogenation of *COOH intermediate is more difficult on Cu 2 O (332). Notably, the hydrogenation of *CO to form *CHO intermediate and the coupling of *CHO to form *OHC‐CHO intermediate are two key steps in the production of C 2 H 4 during the CO 2 RR pathway [16a] . For the former *CO→*CHO step, the change of absorbed Gibbs free energy on Cu 2 O (332) (Δ G =0.56 eV) and Cu 2 O (111) (Δ G =0.55 eV) is lower than that on Cu 2 O (100) (Δ G =0.94 eV).…”

Multiscale CO2 Electrocatalysis to C2+ Products: Reaction Mechanisms, Catalyst Design, and Device Fabrication

“…A similar trend could also be seen on other N-containing molecules or additives. For instance, Cu catalysts modified with urea, polyaniline, poly­(4-vinylpyridine), amino acids, , and polyacrylamide dramatically changed the product distribution by affecting the binding strength of intermediates, enriching gaseous reactants, and providing enhanced wettability. For instance, a high FE acetate of 62% was observed over a Cu–urea system under a potential of −0.37 V vs RHE in a 0.5 M KHCO 3 electrolyte .…”