Enhancing chemical stability and catalytic ability of MOF-303 and Al-TCPP over electrochemical CO₂ reduction: Insights into Cu and Co metalation

The electrochemical reduction of CO₂ (eCO₂RR) presents a promising strategy for mitigating carbon emissions while generating valuable fuels and chemicals. However, the limited chemical stability of metal–organic frameworks (MOFs) in electrochemical environments remains a significant challenge. This study explores the structural robustness and catalytic performance of MOF-303 and Al-TCPP frameworks, modified via Cu and Co metalation, for CO₂ reduction applications. A comprehensive investigation of their physicochemical properties, electrochemical stability across diverse electrolyte conditions, and catalytic efficiency was conducted. Structural integrity was analyzed using powder x-ray diffraction, scanning electron microscopy, Brunauer–Emmett–Teller, x-ray photoelectron spectroscopic, and x-ray absorption spectroscopic techniques, revealing improved stability and electronic tuning upon metalation. Electrochemical studies demonstrated that Cu-functionalized materials favored hydrocarbon production (CH₄, C₂H₄), whereas Co-modified catalysts exhibited high selectivity toward CO formation with suppressed hydrogen evolution. Stability assessments across a broad pH range confirmed superior resilience of Cu-modified MOFs, particularly in neutral and mild alkaline environments. The findings highlight the critical role of post-synthetic metalation in enhancing MOF stability and catalytic selectivity, paving the way for scalable and durable MOF-based eCO₂RR technologies. This work provides valuable insights into rational MOF design strategies for efficient CO₂ electroreduction, contributing to sustainable carbon conversion pathways.