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背景介绍
采用串联的 CO2-to-CO -to-C2+ 的方法可以实现高效的多碳产物转化，同时规避直接 CO2 还原带来的碳酸盐沉积及阴极电解液酸化等问题，近年来在 CO2-to-CO 转化方面已经取得了重大进展，然而开发用于复杂的 CO-to-C2+ 的高性能催化剂仍存在挑战。作为气-液-固三相反应,一氧化碳还原（ECORR）要求电极具有适宜的疏水性以兼顾气体扩散以及离子传导。然而，铜基催化剂由于其表面能较高，往往倾向亲水，使得在长期电解过程中催化层易于被电解液浸没，从而限制了催化层内部的气体接触。
为此，作者提出了一种通过将催化剂与疏水材料复合构建多孔结构的方式，提升催化层气体输运能力，同时，通过催化层表面亲水性的调控实现三相反应界面最大化。本研究提供了一种新的 ECORR 催化剂的设计策略，为进一步开发气相电化学反应的催化层提供了思路。
该成果以“Interface Regulation Promoting Carbon Monoxide Gas Diffusion Electrolysis towards C2+ Products”为题发表在英国皇家学会期刊 Chemical Communications 上，本研究工作得到国家自然科学基金（52072085）的资助。
研究亮点
▲ | Fig 1. Schematic demonstration for the synthesis of Cu@ X%PMMA-MS. a) The fabrication of Cu@X%PMMA-MS is consists of electro-spraying and magnetron sputtering process; b) The morphology of synthesized Cu@ X%PMMA-MS changes with the increase of the PMMA concentration from spheres to fibers |
▲ | Fig 2. Structural characterizations of Cu@8% PMMA. a, b) SEM image of Cu@8% PMMA. c) Pore distribution of Cu@8% PMMA. d) Water contact angle for Cu@8%PMMA and Cu@8%PMMA-MS. e) The triple-phase boundary of the flowing catholyte and the GDE; the gaseous CO reactant and products of interest are highlighted. |
▲ | Fig 3. Electrochemical characterizations in a flow cell. a) Linear sweep voltammetry curves for Cu@8%PMMA-MS, and MS-500s. b) C2+ current density for Cu@8%PMMA-MS, and MS-500s versus applied potentials. c) Current density-dependent C2H4 FE of Cu@8%PMMA-MS, and MS-500s. |
▲ | Fig 4. Mechanistic study through in situ Raman and finite element analysis. a) In situ Raman characterizations of Cu@8%PMMA-MS on GDL during ECORR testing in 1M KOH. b) Finite element analysis of theoretical maximum C2H4 partial current density under various CO mass fractions and catalyst porosity (Gradient pink background), and experimental result for Cu@8%PMMA-MS (top line-point plot). c) Illustration of the catalyst microenvironments and reaction interfaces of Cu@8%PMMA-MS. |
论文信息
Interface Regulation Promoting Carbon Monoxide Gas Diffusion Electrolysis towards C2+ Products
Yingzhang Yan, Yonghao Yu, Yumin Zhang*（张宇民，哈尔滨工业大学， Tai Yao*（姚泰，哈尔滨工业大学） Ping Xu, and Bo Song*（宋波， 哈尔滨工业大学）
Chem. Commun., 2022
http://doi.org/10.1039/D2CC00343K
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