Stabilizing Reticular Frameworks and Modulating Interfacial Water via Conductive Polymer Encapsulation in Metal–Organic Frameworks Electrocatalysts for Efficient Methane Production

The electrochemical reduction of CO 2 to CH 4 offers a promising pathway for renewable energy storage, yet remains limited by sluggish kinetics, poor catalyst stability, and competing hydrogen evolution reactions (HER). Herein, a host–guest strategy is reported for engineering metal–organic frameworks (MOFs) through the encapsulation of conductive polymers to stabilize reticular skeletons and regulate interfacial water for efficient CO 2 –to–CH 4 conversion. Specifically, polypyrrole (PPy) and polyaniline (PANI) are confined within Cu‐anchored UiO‐67 frameworks, resulting in hybrid catalysts—PPy@Cu‐UiO‐67 and PANI@Cu‐UiO‐67—with preserved crystallinity and enhanced electronic conductivity. Among them, PANI@Cu‐UiO‐67 exhibits superior CH 4 Faradaic efficiency (FE CH4 up to 71.1%), outperforming PPy@Cu‐UiO‐67 and unmodified Cu‐UiO‐67. Spectroscopic analysis reveals that the polymers reinforce structural integrity and induce distinct perturbations in the interfacial water network. In situ Raman and attenuated total reflection surface–enhanced infrared absorption spectroscopy measurements identify the dominance of weakly hydrogen–bonded water (2–HB·H 2 O) at the PANI–modified interface, which supports rapid proton transfer while suppressing HER. This study offers a rational design strategy for MOF electrocatalysts by integrating conductive polymers to modulate both the electronic and interfacial environments for high–efficiency methane production.