In situ grown CuSiOX nanoflowers on carbon nanofibers for electrochemical CO2 reduction to methane

Abstract

The electrochemical conversion of CO₂ to valuable hydrocarbons, particularly methane (CH₄), presents a promising approach for combating climate change; however, it remains challenged by competing side reactions and complex multi-electron transfer mechanisms. This study presents a novel catalyst comprising carbon nanofiber-supported amorphous CuSiO₃ (CuSiO₃/CNFs), which demonstrates significantly enhanced CH₄ selectivity. Compared to pure CuSiO₃, the CH₄ selectivity of CuSiO₃/CNFs is increased by up to 1.9 times, achieving a FE_CH4 of 67.8% at −1.6 V (vs. RHE). Remarkably, after 10 h of sustained operation at 100 mA cm⁻² within a flow cell, the FE_CH4 remains above 50%. Characterization through CO₂-TPD and ATR-FTIR reveals that the enhanced performance is attributed to the formation of stable and well-dispersed Cu–O–Si active sites in situ on the CNF surface and the optimized reaction interface that promotes H₂O and CO₂ adsorption and activation. This study offers critical insights into structural regulation strategies for designing effective catalysts for CO₂ reduction, paving the way for advancements in sustainable hydrocarbon production.