Cathodic Disintegration as an Easily Scalable Method for the Production of Sn- and Pb-Based Catalysts for CO₂ Reduction

Abstract

CO 2 electroreduction to formate powered by renewable energy is an attractive strategy to recycle air-based carbon. At the moment, the electrode materials showing high selectivity for formate at high current density are post transition metals such as In, Sn, Bi, and Pb. Scaling up the CO 2 electroreduction technology to industrial size requires, among other things, cheap and clean methods to produce cathode materials in the form of particles to fabricate the square meters of the electrode surface area needed for the industrial electrolyzers. We show here that it is possible to easily produce catalytic powders based on Sn and Pb via a process known as cathodic disintegration, driving the reaction with electric power and avoiding the use of organic solvents, stabilizers, and reducing agents. The catalysts produced with this method are highly selective for the reduction of CO 2 to formate and show promise for use in industrial electrolyzers. Moreover, the process of cathodic disintegration is quick and clean, it has a high atom efficiency, it uses dilute aqueous electrolytes as solvents, and it has the possibility to be driven by renewable energy.

Cathodic Corrosion of Metal Electrodes—How to Prevent It in Electroorganic Synthesis

“…Cathodic etching is another mechanism that can corrode cathodes, and it has been documented in both aqueous ( Scheme 5 , up, a–c) and anhydrous aprotic solvents ( Scheme 5 , down, d–f) for a range of metals including Pt, 75 , 79 , 80 , 97 − 116 Rh, 75 , 97 , 98 , 101 , 102 , 117 Ir, 101 Pd, 98 , 101 , 106 , 107 , 118 , 119 Au, 75 , 97 , 98 , 101 , 117 Ag, 75 , 98 , 101 Cu, 75 , 98 , 101 , 120 Re, 98 Fe, 98 Ni, 75 , 98 , 101 Nb, 75 , 98 Ru, 75 Ti, 98 , 121 − 123 V, 121 W, 121 Si, 75 , 98 Nb, 75 Ru, 75 Al, 98 Pb, 56 , 57 , 124 − 131 Sn, 125 , 127 − 133 Sb, 83 , 91 , 129 , 134 Bi,…”

“…Recently, the involvement of Zintl phases in the cathodic disintegration of Pb, Sn, and Sn50Pb50 cathodes was postulated in aqueous conditions. 131 2.3.1. Cathodic Etching in Anhydrous Aprotic Solvents.…”

System Design Considerations for Enhancing Electroproduction of Formate from Simulated Flue Gas

“…Formic acid is a useful feedstock in the chemical and pharmaceutical industry and also can be directly used as fuel in fuel cells or as a liquid hydrogen carrier . There already exist well-known catalysts that produce formate with high faradaic efficiency (FE) such as SnO x , In, Bi, etc. − Recently, a sulfur incorporated Sn catalyst was reported to achieve a high CO 2 reduction current density and high FE . However, the low solubility of CO 2 in water limits the current density to <100 mA cm –2 in a conventional H-type electrochemical cell setup.…”

Continuous electroconversion of CO2 into formate using 2 nm tin oxide nanoparticles

“…Among the different available electrocatalysts mainly producing formate from CO 2 RR, metallic tin (Sn) appears to be one of the best alternatives in terms of cost and selectivity, highlighting also its low toxicity, even though other metals such as lead (Pb) and bismuth (Bi) have also been proposed as efficient electrocatalysts for formate production [23,[33][34][35][36][37]. Nevertheless, not only the synthesis of small size capping agent free Sn nanoparticles (NPs) is tricky, but also the structural stability of Sn NPs during CO 2 electroreduction is under debate.…”