Cadmium-based metal-organic frameworks for high-performance electrochemical CO2 reduction to CO over wide potential range

Electrochemical CO2 reduction (ECR) powered by renewable energy sources provides a sustainable avenue to producing carbon-neutral fuels and chemicals. The design and development of high performance, cost-effective, and stable catalysts for ECR remain a focus of intense research. Here, we report a novel electrocatalyst, two-dimensional cadmium-based 1,4-benzenedicarboxylate metal-organic frameworks (Cd-BDC MOFs) which can effectively convert CO2 to CO with a faradaic efficiency (FE) of more than 80.0% over the voltage range between -0.9 and -1.1 V (versus reversible hydrogen electrode, vs. RHE) in 0.1 mol.L--(1) CO2-saturated KHCO3 solution with an H-type cell, reaching up to 88.9% at -1.0 V (vs. RHE). The performance outperforms commercial CdO and many other MOF-based materials demonstrated in prior literature. The catalytic property can be readily tuned by manipulating synthesis conditions as well as electrolyte type. Especially, high CO FEs exceeding 90.0% can be attained on the Cd-BDC electrode at potentials ranging from -0.16 to -1.06 V (vs. RHE) in 0.5 mol.L--(1) KHCO3 solution by using a gas diffusion electrode cell system. The maximum CO FE approaches similar to 97.6% at -0.26 V (vs. RHE) and the CO partial geometric current density is as high as about 108.1 mA cm(2) at -1.1 V (vs. RHE). This work offers an efficient, low cost, and alternative electrocatalyst for CO2 transformation. (C) 2021 The Chemical Industry and Engineering Society of China, and Chemical Industry Press Co., Ltd. All rights reserved.

Automated summary

This study presents a novel electrocatalyst that effectively converts CO2 to CO with high faradaic efficiency. The catalyst demonstrates superior performance and can be easily tuned by manipulating synthesis conditions and electrolyte type.