Wang Jiong, Huang Xiang, Xi Shibo, Xu Hu, Wang Xin
School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore, 637459, Singapore.
Department of Physics, Southern University of Science and Technology, Shenzhen, 518055, China.
Angew Chem Int Ed Engl. 2020 Oct 19;59(43):19162-19167. doi: 10.1002/anie.202008759. Epub 2020 Aug 17.
Efficient electron communication between molecular catalyst and support is critical for heterogeneous molecular electrocatalysis and yet it is often overlooked during the catalyst design. Taking CO electro-reduction on tetraphenylporphyrin cobalt (PCo) immobilized onto graphene as an example, we demonstrate that adding a relay molecule improves the interfacial electron communication. While the directly immobilized PCo on graphene exhibits relatively poor electron communications, it is found that diphenyl sulfide serves as an axial ligand for PCo and it improves the redox activity of PCo on the graphene surface to facilitate the generation of [PCo] - active sites for CO reduction. Thus, the turnover frequencies of the immobilized Co complexes are increased. Systematic structural analysis indicates that the benzene rings of diphenyl sulfide exhibit strong face-to-face stacking with graphene, which is proposed as an efficient medium to facilitate the interfacial electron communication.
分子催化剂与载体之间高效的电子通信对于多相分子电催化至关重要，但在催化剂设计过程中却常常被忽视。以固定在石墨烯上的四苯基卟啉钴（PCo）上的CO电还原为例，我们证明添加中继分子可改善界面电子通信。虽然直接固定在石墨烯上的PCo表现出相对较差的电子通信，但发现二苯硫醚作为PCo的轴向配体，它提高了PCo在石墨烯表面的氧化还原活性，以促进用于CO还原的[PCo] - 活性位点的产生。因此，固定化钴配合物的周转频率增加。系统的结构分析表明，二苯硫醚的苯环与石墨烯表现出强烈的面对面堆积，这被认为是促进界面电子通信的有效介质。
