posted on 2024-01-03, 22:07authored byZhejiaji Zhu, Yuhao Zhu, Zhixin Ren, Di Liu, Feiyu Yue, Dafei Sheng, Pengpeng Shao, Xiuying Huang, Xiao Feng, An-Xiang Yin, Jing Xie, Bo Wang
CO2 electroreduction holds great promise for
addressing
global energy and sustainability challenges. Copper (Cu) shows great
potential for effective conversion of CO2 toward specific
value-added and/or high-energy-density products. However, its limitation
lies in relatively low product selectivity. Herein, we present that
the CO2 reduction reaction (CO2RR) pathway on
commercially available Cu can be rationally steered by modulating
the microenvironment in the vicinity of the Cu surface with two-dimensional
sulfonated covalent organic framework nanosheet (COF-NS)-based ionomers.
Specifically, the selectivity toward methane (CH4) can
be enhanced to more than 60% with the total current density up to
500 mA cm–2 in flow cells in both acidic (pH = 2)
and alkaline (pH = 14) electrolytes. The COF-NS, characterized by
abundant apertures, can promote the accumulation of CO2 and K+ near the catalyst surface, alter the adsorption
energy and surface coverage of *CO, facilitate the dissociation of
H2O, and finally modulate the reaction pathway for the
CO2RR. Our approach demonstrates the rational modulation
of reaction interfaces for the CO2RR utilizing porous open
framework ionomers, showcasing their potential practical applications.