Pulsed Strategy Steers the Structural Evolution of Cu Metal–Organic Framework for CO<sub>2</sub> Reduction to Methane
Jiayi Huang, Xiang‐Da Zhang, Han Yang, Qianwen Liu, Wei-Wen Yuan, Wenchuan Lai, Zhi‐Yuan Gu
Abstract
Abstract The electrochemical CO 2 reduction reaction (CO 2 RR) to produce hydrocarbon fuels, such as methane (CH 4 ), offers a promising pathway to address the dual challenges of climate change and energy shortage. Although copper‐based metal‐organic frameworks (Cu‐MOFs) have proven to be promising CO 2 RR catalysts for hydrocarbon production, their uncontrollable structural reconstruction under operating conditions leads to elusive active sites. Herein, we demonstrate that a pulsed potential electrolysis strategy with well‐designed pulse parameters can steer the dynamic reconstruction of Cu‐MOFs to customize the active sites to enable the CH 4 formation pathway. Mechanistic studies using electron microscopic and spectroscopic methods indicated that constant‐potential electrolysis caused the rapid reduction of Cu‐MOF to metallic Cu nanoparticles, whereas pulsed electrolysis enabled the controlled generation of active Cu 2 O/CuO nanoclusters. Benefiting from this, the pulsed system delivers an exceptional Faradaic efficiency (FE) of 82.9% in CH 4 production from the CO 2 RR. This selectivity markedly surpasses that of the constant‐potential counterpart, representing the state‐of‐the‐art. In addition, this approach facilitates stable CH 4 production for over 12 hours while maintaining an FE above 60%.