Recent advances in thermal catalytic hydrogenation of carbon dioxide to ethanol

The hydrogenation of carbon dioxide (CO2) to ethanol (EtOH) represents a promising strategy for carbon resource utilization. This progress advances the fields of green chemistry and renewable energy technologies. However, its practical implementation remains hindered by challenges in catalyst development, reaction mechanism elucidation, and industrial scalability. The reaction pathway for CO2 hydrogenation to EtOH is intricate, involving C–O bond activation and C–C coupling, with its thermodynamic and kinetic properties strongly influenced by temperature, pressure, and catalyst structure. Briefly, CO2 conversion rate and EtOH selectivity are significantly enhanced by optimizing catalyst active sites, incorporating promoters and selecting appropriate supports. In recent years, multifunctional catalysts have emerged as research hotspots due to their facile structural design and superior catalytic performance. Here, it reviews the reaction mechanisms, catalyst design principles, and optimization strategies for CO2 hydrogenation to EtOH in the continuous-flow fixed-bed reactor with a particular emphasis on the roles of noble metals (e.g., Rh) and transition metals (e.g., Co, Cu) in this reaction. Future investigations should focus on deepening the mechanistic understanding of the reaction, developing efficient and stable catalysts, and optimizing the reaction conditions to enable the industrial-scale application of CO2 hydrogenation to EtOH in the continuous-flow fixed-bed reactor, thereby advancing green chemistry and sustainable development.

二氧化碳（CO₂）加氢制备乙醇（EtOH）是极具前景的碳资源利用策略，该方向推动了绿色化学与可再生能源技术领域的发展。然而，其实际应用仍受限于催化剂开发、反应机制阐明以及工业规模化生产等方面的挑战。二氧化碳加氢制乙醇的反应路径极为复杂，涉及碳氧键活化与碳碳偶联过程，其热力学与动力学特性显著受温度、压力及催化剂结构的影响。简而言之，优化催化剂活性位点、引入助剂以及选择合适的载体，可大幅提升二氧化碳转化率与乙醇选择性。近年来，多功能催化剂凭借简便的结构设计与优异的催化性能成为研究热点。本文综述了连续流动固定床反应器（continuous-flow fixed-bed reactor）中二氧化碳加氢制乙醇的反应机制、催化剂设计原则及优化策略，重点探讨了贵金属（如铑Rh）与过渡金属（如钴Co、铜Cu）在该反应中的作用。未来研究应聚焦于深化该反应的机制认知、开发高效稳定的催化剂以及优化反应条件，以实现二氧化碳加氢制乙醇技术在连续流动固定床反应器中的工业规模化应用，进而推动绿色化学与可持续发展。