Carbon-Based Catalysts for Electrochemical CO2 Reduction
Fossil fuel energy gives rise to various global issues including aggravated greenhouse gas carbon dioxide (CO2) emission, which deteriorates the surrounding environment such as global warming and melting glaciers. Electrochemical CO2 reduction is regarded as a promising method to convert CO2 back into valuable chemicals and fuels, inparticular when the electricity if generated from renewable sources such as solar and wind. Carbonaceous materials are considered to be promising catalysts for this purpose due to their excellent electroconductivity, high surface area and low cost. Normally, carbon-based materials have no activity because of electroneutral carbon atoms. To design carbonaceous catalysts with superoir activity, various efficient and convenient strategies have been reported in recent years. In this review, we firstly provide a sketch about doping heteroatoms into carbon structure which can break the electroneutrally of carbon frameworks and enhance the adsorption capacity of CO2 intermediate. Furthermore, transition metal-nitrogen-carbon system is summarized as a highly efficient structure for CO2 reduction. In addition, a series of reports representative of carbon substrates combined with different types of functional groups such as metal particles, metal oxides, metal complexes and even metal-free functional groups are reviewed. Finally, we highlight some potential limitations for the reported catalytic systems which hopefully can direct researchers to investigate new carbon-based catalysts and synthesis strategies for the development of electrochemical CO2 reduction in the future.