Lithium Vacancy-Tuned [CuO4 ] Sites for Selective CO2 Electroreduction to C2+ Products

Chen Peng; Xiaorong Zhu; Zikai Xu; Shuai Yan; Lo Yueh Chang; Zhiqiang Wang; Junbo Zhang; Menghuan Chen; Tsun-Kong Sham; Yafei Li; Gengfeng Zheng

doi:10.1002/smll.202106433

Lithium Vacancy-Tuned [CuO₄ ] Sites for Selective CO₂ Electroreduction to C₂₊ Products

Small. 2022 Feb;18(8):e2106433. doi: 10.1002/smll.202106433. Epub 2021 Dec 12.

Authors

Affiliations

¹ Laboratory of Advanced Materials, Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Faculty of Chemistry and Materials Science, Fudan University, Shanghai, 200438, China.
² Jiangsu Key Laboratory of New Power Batteries, Jiangsu Collaborative Innovation Centre of Biomedical Functional Materials, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing, 210023, China.
³ Institute of Functional Nano and Soft Materials (FUNSOM), Joint International Research Laboratory of Carbon-Based Functional Materials and Devices, Soochow University, Suzhou, Jiangsu, 215123, China.
⁴ Department of Chemistry, University of Western Ontario, 1151 Richmond Street, London, ON, N6A 5B7, Canada.

PMID: 34898005
DOI: 10.1002/smll.202106433

Abstract

Electrochemical CO₂ reduction to valuable multi-carbon (C₂₊ ) products is attractive but with poor selectivity and activity due to the low-efficient CC coupling. Herein, a lithium vacancy-tuned Li₂ CuO₂ with square-planar [CuO₄ ] layers is developed via an electrochemical delithiation strategy. Density functional theory calculations reveal that the lithium vacancies (V_Li ) lead to a shorter distance between adjacent [CuO₄ ] layers and reduce the coordination number of Li⁺ around each Cu, featuring with a lower energy barrier for COCO coupling than pristine Li₂ CuO₂ without V_Li . With the V_Li percentage of ≈1.6%, the Li_2- _x CuO₂ catalyst exhibits a high Faradaic efficiency of 90.6 ± 7.6% for C₂₊ at -0.85 V versus reversible hydrogen electrode without iR correction, and an outstanding partial current density of -706 ± 32 mA cm^-2 . This work suggests an attractive approach to create controllable alkali metal vacancy-tuned Cu catalytic sites toward C₂₊ products in electrochemical CO₂ reduction.

Keywords: C 2+ products; CO 2 reduction reaction; Li 2CuO 2; electrochemical delithiation; lithium vacancies.

Abstract

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