Selective CO2 electrolysis to CO using isolated antimony alloyed copper

Abstract

Renewable electricity-powered CO evolution from CO2 emissions is a promising first step in the sustainable production of commodity chemicals, but performing electrochemical CO2 reduction economically at scale is challenging since only noble metals, for example, gold and silver, have shown high performance for CO2-to-CO. Cu is a potential catalyst to achieve CO2 reduction to CO at the industrial scale, but the C-C coupling process on Cu significantly depletes CO* intermediates, thus limiting the CO evolution rate and producing many hydrocarbon and oxygenate mixtures. Herein, we tune the CO selectivity of Cu by alloying a second metal Sb into Cu, and report an antimony-copper single-atom alloy catalyst (Sb1Cu) of isolated Sb-Cu interfaces that catalyzes the efficient conversion of CO2-to-CO with a Faradaic efficiency over 95%. The partial current density reaches 452 mA cm−2 with approximately 91% CO Faradaic efficiency, and negligible C2+ products are observed. In situ spectroscopic measurements and theoretical simulations reason that the atomic Sb-Cu interface in Cu promotes CO2 adsorption/activation and weakens the binding strength of CO*, which ends up with enhanced CO selectivity and production rates.

Ag–Sb/Cu by Galvanic Replacement: Electrochemical CO2 Reduction and Unveiling C3+ Hydrocarbon Pathways

“…H 2 production, a well-known path initiated from H + + e – → H*, is a common dominant route. The two-electron process for CO involves the reactions CO 2 + H + + e – → *COOH, followed by *COOH + H + + e – → *CO + H 2 O. − ,,, Similarly, the two-electron process for formate is known to occur through CO 2 + H + + e – → OCHO* and OCHO* + e – → HCOO – . − , The adsorption of two intermediate species, *COOH and *CHO*, determines the final products and is highly dependent on the nature of the developed electrodes and the experimental conditions. The initiation of C 1 products, CH 4 , and methanol appears to involve the hydrogenation of surface *CO, following reactions such as *CO + H + + e – → *CHO or *COH.…”

Optimizing Pt-Based Alloy Electrocatalysts for Improved Hydrogen Evolution Performance in Alkaline Electrolytes: A Comprehensive Review

“…These catalysts present unsaturated coordination environments and a particular electronic structure. Single metal atoms, particularly noble metal single atoms, can be also dispersed on the surface of another metal in an alloy to form a single-atom catalyst alloy with structural characteristics of both single-atom and alloy catalysts. − Thus, alloying advantages, such as electronic tuning and active phase dispersion, and single-atom catalysts, such as 100% atom efficiency, can be combined in a single system.…”

Cu-based catalyst designs in CO2 electroreduction: precise modulation of reaction intermediates for high-value chemical generation

“…Computational simulations indicate that Sb doping promotes CO 2 adsorption and activation while facilitating the desorption of *CO during the reaction, significantly improving CO selectivity. 59 Introducing Pd to Cu creates a strong affinity for CO* and effectively inhibits hydrogen precipitation, resulting in a single-pass carbon efficiency of 60% for CO 2 to C 2+ at 500 mA cm −2 under acidic conditions. 109 Doping Cu with another metal atom can impact not only the charge distribution of the Cu surface but also other aspects like the catalyst's morphology.…”