Electron-Withdrawing Ligands Boost Dilute CO₂ Electrolysis

The efficient production of valuable multicarbon (C2+) chemicals via direct electrolysis of dilute CO2 derived from industrial flue gases is a promising route to close the carbon cycle, but is not yet practical owing to insufficient electrocatalytic performance limited by sluggish reaction kinetics at low CO2 concentrations. Despite considerable advances in the generation of C1products such as CO and formate, with Faradaic efficiencies exceeding 90% through rational catalyst design, selective production of C2+ hydrocarbons and oxygenates remains a major bottleneck. Unlike C1 pathways that typically follow first‑order kinetics, C2+ formation relies on C−C coupling and exhibits higher reaction order, making the enrichment of key intermediates such as *CO indispensable for surmounting the C−C coupling barrier.

Recently, a research team led by Prof. Dunfeng Gao and Prof. Tianfu Liu from the Dalian Institute of Chemical Physics, Chinese Academy of Sciences employed a set of Cu‑BDC‑X (BDC: 1,4-benzenedicarboxylic acid; X : −H, −F, −NH2) metal organic framework (MOFs)as pre‑catalyststo in situgenerateligand‑modified Cu nanoparticles through electrochemical reconstruction during CO2 electrolysis. The electron‑withdrawing −F group modulates the electron density of Cu active sites, which strengthens *CO adsorption and reduces the C−C coupling energy barrier, thus facilitating multicarbon product formation.The results were published in Chinese Journal of Catalysis (DOI: 10.1016/S1872-2067(26)65151-0 ).

Upon CO2 electrolysis, the Cu‑BDC‑X MOFpre‑catalystsunderwent prominent insitu electrochemical reconstruction: Cu2+ centers were reduced into metallic Cu nanoparticles, whereas BDC‑X organic linkers remained anchored on the nanoparticle surface to achieve surface functionalization. Performance evaluation for dilute CO2 electrolysis was implemented in a zero‑gap alkaline membraneelectrodeassembly (MEA) electrolyzer. Owing to the strong electron‑withdrawing ability of the −F group, the Cu‑BDC‑F pre-catalyst achieved a C2+ Faradaic efficiency of 67.9 % and a maximum C2+ partial current density of 130 mA cm−2 under a 15 % CO2 feed at 0.4 MPa.

A combination of spectroscopic characterizations and theoretical calculations uncovered the underlying structure-performance correlations of these Cu‑BDC‑X MOF pre‑catalysts. The electron‑withdrawing −F group reduced the electron density of Cu active sites, which improves *CO adsorption and lowers energy barrier for C−C coupling, thus resulting in improved C2+ selectivity.This work underscores the importance of tuning electronic structures for the rational design of efficient catalysts towards direct dilute CO2 electrolysis to valuable chemicals.

About the Journal

Chinese Journal of Catalysis is co-sponsored by Dalian Institute of Chemical Physics, Chinese Academy of Sciences and Chinese Chemical Society, and it is currently published by Elsevier group. This monthly journal publishes in English timely contributions of original and rigorously reviewed manuscripts covering all areas of catalysis. The journal publishes Reviews, Accounts, Communications, Articles, Highlights, Perspectives, and Viewpoints of highly scientific values that help understanding and defining of new concepts in both fundamental issues and practical applications of catalysis. Chinese Journal of Catalysis ranks among the top six journals in Applied Chemistry with a current SCI impact factor of 17.2. The Editors-in-Chief are Profs. Can Li and Tao Zhang.

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