Wang Yang, Jiang Zhan, Zhang Xiao, Niu Zeyu, Zhou Qinqi, Wang Xiaojun, Li Huan, Lin Zhichao, Zheng Hongzhi, Liang Yongye
School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China.
Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
ACS Appl Mater Interfaces. 2020 Jul 29;12(30):33795-33802. doi: 10.1021/acsami.0c08940. Epub 2020 Jul 17.
Single-atom catalysts (SACs) with atomically dispersed metal sites in nitrogen-doped carbon matrices (M-N/C) have been identified as promising candidates for the electrocatalytic CO reduction reaction (CORR). However, recent studies aiming at economic viability have been inhibited by the low faradaic efficiency (FE) and instability under high current density. Herein, we report a series of SACs derived from cyano-substituted metal phthalocyanines (MePc-CN) in ZIFs (denoted as Me-SACs (Pc)). These phthalocyanine molecules enable the efficient construction of SACs, affording higher metal loading and less variation when compared with their counterparts from metal nitrates (denoted as Me-SACs (S)). Thus, Me-SACs (Pc) exhibit higher activities and selectivities than Me-SACs (S) in H-cell measurements. In gas-diffusion electrode (GDE) setups, the unstable Fe-SAC (Pc) shows only a 50% FE of CO (FEco) at -100 mA cm. In contrast, Ni-SAC (Pc) exhibits a higher FEco of >96% at current densities from -10 to -200 mA cm and can stably operate for over 16 h at -200 mA cm. The performances of Ni-SAC (Pc) are comparable to those of precious metal catalysts and the best SACs reported so far, representing a promising candidate for practical electrolyzer devices for CORR.
在氮掺杂碳基体（M-N/C）中具有原子分散金属位点的单原子催化剂（SACs）已被认为是电催化CO还原反应（CORR）的有前途的候选者。然而，最近针对经济可行性的研究受到低法拉第效率（FE）和高电流密度下不稳定性的抑制。在此，我们报告了一系列源自ZIFs中氰基取代金属酞菁（MePc-CN）的SACs（表示为Me-SACs（Pc））。这些酞菁分子能够高效构建SACs，与来自金属硝酸盐的对应物（表示为Me-SACs（S））相比，具有更高的金属负载量和更小的变化。因此，在H型电池测量中，Me-SACs（Pc）比Me-SACs（S）表现出更高的活性和选择性。在气体扩散电极（GDE）装置中，不稳定的Fe-SAC（Pc）在-100 mA cm时仅显示50%的CO法拉第效率（FEco）。相比之下，Ni-SAC（Pc）在-10至-200 mA cm的电流密度下表现出>96%的更高FEco，并且在-200 mA cm时可以稳定运行超过16小时。Ni-SAC（Pc）的性能与贵金属催化剂和迄今为止报道的最佳SACs相当，是CORR实际电解槽装置的有前途的候选者。
