In-situ grafting of cobalt phthalocyanine on gas diffusion electrodes enables ampere-level CO<sub>2</sub> reduction.

Yan, Huihui; He, Gaoxiang; Fan, Rongli; Zhao, Minyue; Huang, Huiting; Lin, Zhexing; Gao, Bin; Feng, Jianyong et al. · Nat Commun · 2025

basic_science · Level V

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Abstract

Immobilizing molecular catalysts onto gas diffusion electrodes (GDEs) through covalent bonds provides a strategy to circumvent their issues of aggregation, detachment and poor conductivity during CO<sub>2</sub> electrolysis. However, this approach has been limited to catalysts equipped with specially designed functional groups, and directly covalent grafting of pristine molecular catalysts onto GDEs remains a formidable challenge. Herein, using pristine cobalt phthalocyanine (CoPc) as a model catalyst, we propose a polypyrrole (ppy) mediated electro-polymerization strategy that creates robust C-C bonds between GDEs and pristine CoPc. In this scheme, ppy acts as both the conductive linker and scaffold for pristine CoPc, and its electron donation effects further enhances the CO<sub>2</sub> electrolysis activity of CoPc centres. Here we show that the assembled CO<sub>2</sub> electrolyzer using CoPc/ppy/GDE electrode achieves stable operation for 120 h at 500 mA cm<sup>-2</sup> and 50 h at 1 A cm<sup>-2</sup> in alkaline media. When coupled with a triple-junction solar cell, the resulting photovoltaic-electrolysis system attains a solar-to-CO efficiency of 19.2%.