Research Progress on Cobalt-Based Catalysts for the Hydrogenation of Carbon Dioxide to Ethanol
The catalytic hydrogenation of CO2 to ethanol is a pivotal technology for carbon neutrality and high-value chemical production. Cobalt-based catalysts, with their unique electronic structure and tunability, are promising for this reaction, yet challenges persist: low single-pass CO2 conversion, ethanol selectivity below 60%, and rapid deactivation. This review systematically analyzes recent progress, establishing the thermodynamic and kinetic framework, and dissecting molecular-level mechanisms, particularly C–C bond formation and controlled oxygen removal. It critically evaluates synergistic effects among metallic Co, Co2C, CoOx, and bimetallic configurations, emphasizing structure-activity relationships influenced by supports and promoters. Inverse catalysts and tandem systems are reviewed, along with water's role as a hydrogen source. The review identifies shortcomings and advocates for advanced in situ/operational characterization and theoretical modeling to guide next-generation catalyst design. Key findings from cited studies include: Co/La4Ga2O9 achieving high selectivity (reference [85]); K-loaded Cu/CoOx boosting ethanol production (reference [86]); Ga-promoted CuCo catalysts with Cu-CoGaOx interfacial sites (reference [88]); and Mo-tailored CoFe alloys suppressing over-carburization (reference [89]). These insights provide a framework for developing efficient cobalt-based systems, deepening mechanistic understanding, and accelerating sustainable ethanol production.