Wang Xiaoyue, Zeng Ting, Guo Xiaohong, Yan Zhiqiang, Ban Hongyan, Yao Ruwei, Li Congming, Gu Xiang-Kui, Ding Mingyue
State Key Laboratory of Clean and Efficient Coal Utilization, College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan, Shanxi 030024, China.
School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072, China.
Proc Natl Acad Sci U S A. 2024 Sep 10;121(37):e2408297121. doi: 10.1073/pnas.2408297121. Epub 2024 Sep 5.
Catalytic hydrogenation of CO to value-added fuels and chemicals is of great importance to carbon neutrality but suffers from an activity-selectivity trade-off, leading to limited catalytic performance. Herein, the ZnFeAlO + SAPO-34 composite catalyst was designed, which can simultaneously achieve a CO conversion of 42%, a CO selectivity of 50%, and a C-C selectivity of 83%, resulting in a C-C yield of almost 18%. This superior catalytic performance was found to be from the presence of unconventional electron-deficient tetrahedral Fe sites and electron-enriched octahedral Zn sites in the ZnFeAlO spinel, which were active for the CO deoxygenation to CO via the reverse water gas shift reaction, and CO hydrogenation to CHOH, respectively, leading to a route for CO hydrogenation to C-C, where the kinetics of CO activation can be improved, the mass transfer of CO hydrogenation can be minimized, and the C-C selectivity can be enhanced via modifying the acid density of SAPO-34. Moreover, the spinel structure of ZnFeAlO possessed a strong ability to stabilize the active Fe and Zn sites even at elevated temperatures, resulting in long-term stability of over 450 h for this process, exhibiting great potential for large-scale applications.
将CO催化氢化为增值燃料和化学品对碳中和具有重要意义，但存在活性-选择性权衡问题，导致催化性能受限。在此，设计了ZnFeAlO + SAPO-34复合催化剂，其可同时实现42%的CO转化率、50%的CO选择性和83%的C-C选择性，从而实现近18%的C-C产率。发现这种优异的催化性能源于ZnFeAlO尖晶石中存在非常规的缺电子四面体Fe位点和富电子八面体Zn位点，它们分别对通过逆水煤气变换反应将CO脱氧为CO以及将CO氢化为CHOH具有活性，从而形成了一条将CO氢化为C-C的途径，在此途径中，CO活化的动力学可以得到改善，CO氢化的传质可以最小化，并且通过改变SAPO-34的酸密度可以提高C-C选择性。此外，ZnFeAlO的尖晶石结构即使在高温下也具有很强的稳定活性Fe和Zn位点的能力，导致该过程具有超过450 h的长期稳定性，展现出大规模应用的巨大潜力。
