Yang Haozhou, Guo Na, Xi Shibo, Wu Yao, Yao Bingqing, He Qian, Zhang Chun, Wang Lei
Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore, Singapore.
National University of Singapore (Chongqing) Research Institute, Building 4, Internet Industrial Park Phase 2, Chongqing Liang Jiang New Area, Chongqing, China.
Nat Commun. 2024 Sep 4;15(1):7703. doi: 10.1038/s41467-024-52168-x.
Cobalt phthalocyanine immobilized on carbon nanotube has demonstrated appreciable selectivity and activity for methanol synthesis in electrocatalytic CO/CO reduction. However, discrepancies in methanol production selectivity and activity between CO and CO reduction have been observed, leading to inconclusive mechanisms for methanol production in this system. Here, we discover that the interaction between cobalt phthalocyanine molecules and defects on carbon nanotube substrate plays a key role in methanol production during CO/CO electroreduction. Through detailed operando X-ray absorption and infrared spectroscopies, we find that upon application of cathodic potential, this interaction induces the transformation of the planar CoN center in cobalt phthalocyanine to an out-of-plane distorted configuration. Consequently, this potential induced structural change promotes the transformation of linearly bonded *CO at the CoN center to bridge *CO, thereby facilitating methanol production. Overall, these comprehensive mechanistic investigations and the outstanding performance (methanol partial current density over 150 mA cm) provide valuable insights in guiding the activity and selectivity of immobilized cobalt phthalocyanine for methanol production in CO/CO reduction.
固定在碳纳米管上的钴酞菁在电催化CO/CO还原制甲醇反应中表现出可观的选择性和活性。然而，已观察到CO和CO还原制甲醇的选择性和活性存在差异，导致该体系中甲醇生成的机理尚无定论。在此，我们发现钴酞菁分子与碳纳米管基底上的缺陷之间的相互作用在CO/CO电还原制甲醇过程中起关键作用。通过详细的原位X射线吸收和红外光谱，我们发现施加阴极电位时，这种相互作用会使钴酞菁中的平面CoN中心转变为面外扭曲构型。因此，这种电位诱导的结构变化促进了CoN中心处线性键合的CO向桥式CO的转变，从而有利于甲醇的生成。总体而言，这些全面的机理研究以及出色的性能（甲醇分电流密度超过150 mA cm）为指导固定化钴酞菁在CO/CO还原制甲醇中的活性和选择性提供了有价值的见解。
