Designing Cu-Based Tandem Catalysts for CO₂ Electroreduction Based on Mass Transport of CO Intermediate

Abstract

Electrochemical reduction of CO2 to high-value hydrocarbons and oxygenates is an attractive technique to store intermittent renewable energy. Diverse catalysts are capable of catalyzing the CO2 to CO conversion, while further reduction of CO occurs almost exclusively on Cu. Monocomponent Cu catalysts suffer from the high overpotential and low Faradaic efficiency of hydrocarbons and oxygenates. Combining CO2 to CO conversion on Au, Ag, single-atom catalysts, etc., with CO reduction on Cu is a promising strategy to achieve high selectivity and a high formation rate of highly reduced products. Numerous tandem catalysts have been developed based on this idea, and the mass transport of a CO intermediate from a CO-formation catalyst to Cu is the key factor that needs to be considered in the design of tandem catalysts. Rational analysis of the different modes of CO mass transport in the reported designs is needed for further development of tandem catalysts for CO2 reduction. In this review, we elucidate how the spatial distribution of the CO-formation catalyst and Cu determines the mode of CO mass transport and consequently affects the utilization efficiency and reduction rate of the CO intermediate. We also discuss the challenges and perspectives in understanding the interaction between the CO-formation catalyst and Cu and improving their catalytic performance in the CO2 tandem reduction.

Design strategy of a Cu-based catalyst for optimizing the performance in the electrochemical CO2reduction reaction to multicarbon alcohols

“…The tandem catalyst is to connect a catalyst that efficiently generates CO and a Cu catalyst in series, which can not only promote the conversion of CO 2 to CO but also accelerate the C-C coupling on the Cu catalyst. 88 The efficient transport of CO to Cu catalysts is the key to the design of tandem catalysts. 88 Zhang et al 77 prepared Cu@Ag core-shell nanoparticles with different silver layer thicknesses for the tandem catalysis of CO 2 conversion by generating CO on the Ag shell and further realizing C-C coupling on the Cu core.…”

“…88 The efficient transport of CO to Cu catalysts is the key to the design of tandem catalysts. 88 Zhang et al 77 prepared Cu@Ag core-shell nanoparticles with different silver layer thicknesses for the tandem catalysis of CO 2 conversion by generating CO on the Ag shell and further realizing C-C coupling on the Cu core. The FE values of the total C 2 product, ethylene, and ethanol of the Cu@Ag core-shell nanoparticle catalyst were 67.6%, 32.2%, and 30.4% at −1.1 V vs. RHE, respectively.…”

“…The tandem catalyst is to connect a catalyst that efficiently generates CO and a Cu catalyst in series, which can not only promote the conversion of CO 2 to CO but also accelerate the C–C coupling on the Cu catalyst. 88 The efficient transport of CO to Cu catalysts is the key to the design of tandem catalysts. 88…”

The spatial distribution of cobalt phthalocyanine and copper nanocubes controls the selectivity towards C2 products in tandem electrocatalytic CO2 reduction

“…5 Cu-based tandem schemes have emerged as a valid strategy to enhance the selectivity of CO 2 RR towards multicarbon products (C 2+ ) by decoupling the CO 2 to CO and the CO to C 2+ reduction steps. [6][7][8][9] Previous work has demonstrated that increasing the local concentration of CO and/or the surface coverage of adsorbed CO (*CO) decreases the energetic barrier for C-C coupling, which is the rate-determining step towards C 2+ products on Cu surfaces. [10][11][12][13][14][15][16][17] In addition to their intrinsic catalytic properties (i.e.…”

Geometric Catalyst Utilization in Zero-Gap CO2 Electrolyzers

“…A way of combining these mass transport effects is by considering geometric catalyst utilization of a CO 2 electrolyzer, which can then be defined as the ratio of the planar catalyst area utilized for CO 2 RR (desired reaction) to the total planar catalyst area present in the system. Recent studies have considered broader mass transport efforts for mapping spatial electrochemical activity and engineering catalyst layers for maximizing multicarbon products from CO 2 RR, − but these have yet to be considered as changing in time.…”