Electrochemical CO2 reduction is the cathodic conversion of carbon dioxide into carbon monoxide, formate, hydrocarbons or alcohols, driven by electricity at an electrode surface whose structure decides which intermediates are stabilised. Selectivity rather than activity is the central problem, because the competing hydrogen evolution reaction shares the potential window and often the active site, and catalyst design therefore has to be considered together with mass transport [1]. Reactor configuration matters as much as catalyst identity: gas-diffusion electrodes, electrolyte composition and cell geometry set the local concentration at the interface and hence which pathway dominates [2]. Bismuth, tin and indium cathodes give formate with high faradaic efficiency because their surfaces favour the adsorbed precursor over carbon monoxide [3]. Bimetallic oxides shift selectivity through interface sites rather than through either component alone [4], while molecular catalysts, metalloporphyrins among them, offer defined sites whose mechanism can be computed directly [5]. Comparing reports across cells stays difficult because local pH and transport are rarely documented together.
- carbon dioxide reduction
- faradaic efficiency
- gas diffusion electrode
- product selectivity
- copper catalyst
- reaction intermediate
- carbon monoxide
References
- Alfath, M.; Lee, C.W.; Recent Advances in the Catalyst Design and Mass Transport Control for the Electrochemical Reduction of Carbon Dioxide to Formate. Catalysts 2020, 10, 859, 10.3390/catal10080859.
- Nankya, R.; Elgazzar, A.; Zhu, P.; Chen, F.Y.; Wang, H.; Catalyst design and reactor engineering for electrochemical CO2 reduction to formate and formic acid. Materials Today 2024, 76, 94-109, 10.1016/j.mattod.2024.05.002.
- Hegner, R.; Rosa, L.F.; Harnisch, F.; Electrochemical CO2 reduction to formate at indium electrodes with high efficiency and selectivity in pH neutral electrolytes. Applied Catalysis B: Environmental 2018, 238, 546-556, 10.1016/j.apcatb.2018.07.030.
- Azenha, C.; Mateos-Pedrero, C.; Lagarteira, T.; Mendes, A.M.; Tuning the selectivity of Cu2O/ZnO catalyst for CO2 electrochemical reduction. Journal of CO2 Utilization 2023, 68, 102368, 10.1016/j.jcou.2022.102368.
- Masood, Z.; Ge, Q.; Mechanism and Selectivity of Electrochemical Reduction of CO2 on Metalloporphyrin Catalysts from DFT Studies. Molecules 2023, 28, 375, 10.3390/molecules28010375.