Gao Fei, Wu Ya-Pan, Wu Xue-Qian, Li Dong-Sheng, Yang Guoping, Wang Yao-Yu
Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, Shaanxi Key Laboratory of Physico-Inorganic Chemistry, College of Chemistry & Materials Science, Northwest University, Xi'an 710127, P. R. China.
College of Materials and Chemical Engineering, Hubei Provincial Collaborative Innovation Center for New Energy Microgrid, Key Laboratory of Inorganic Nonmetallic Crystalline and Energy Conversion Materials, China Three Gorges University, Yichang 443002, P. R. China.
Inorg Chem. 2024 May 13;63(19):8948-8957. doi: 10.1021/acs.inorgchem.4c01049. Epub 2024 Apr 30.
Excellent electrocatalytic CO reduction reaction activity has been demonstrated by transition metals and nitrogen-codoped carbon (M-N-C) catalysts, especially for transition-metal porphyrin (MTPP)-based catalysts. In this work, we propose to use one-step low-temperature pyrolysis of the isostructural MTPP-based metal-organic frameworks (MOFs) and electrochemical in situ reduction strategies to obtain a series of hybrid catalysts of Co nanoparticles (Co NPs) and MTPP, named Co NPs/MTPP (M = Fe, Co, and Ni). The in situ introduction of Co NPs can efficiently enhance the electrocatalytic ability of MTPP (M = Fe, Co, and Ni) to convert CO to CO, particularly for FeTPP. Co NPs/FeTPP endowed a high CO faradaic efficiency (FE = 95.5%) in the H cell, and the FE > 90.0% is in the broad potential range of -0.72 to -1.22 V. In addition, the Co NPs/FeTPP achieved 145.4 mA cm at a lower potential of -0.70 V with an FE of 94.7%, and the CO partial currents increased quickly to reach 202.2 mA cm at -0.80 V with an FE of 91.6% in the flow cell. It is confirmed that Co NPs are necessary for hybrid catalysts to get superior electrocatalytic activity; Co NPs also can accelerate HO dissociation and boost the proton supply capacity to hasten the proton-coupled electron-transfer process, effectively adjusting the adsorption strength of the reaction intermediates.
过渡金属与氮共掺杂碳（M-N-C）催化剂已展现出优异的电催化CO还原反应活性，尤其是基于过渡金属卟啉（MTPP）的催化剂。在本工作中，我们提出采用基于等结构MTPP的金属有机框架（MOF）的一步低温热解和电化学原位还原策略，以获得一系列钴纳米颗粒（Co NPs）与MTPP的混合催化剂，命名为Co NPs/MTPP（M = Fe、Co和Ni）。Co NPs的原位引入可有效增强MTPP（M = Fe、Co和Ni）将CO转化为CO的电催化能力，特别是对于FeTPP。Co NPs/FeTPP在H型电解池中赋予了较高的CO法拉第效率（FE = 95.5%），并且在-0.72至-1.22 V的宽电位范围内FE > 90.0%。此外，Co NPs/FeTPP在-0.70 V的较低电位下实现了145.4 mA cm，FE为94.7%，在流通池中，当电位为-0.80 V、FE为91.6%时，CO分电流迅速增加至202.2 mA cm。证实了Co NPs对于混合催化剂获得优异的电催化活性是必要的；Co NPs还可加速HO解离并提高质子供应能力，以加速质子耦合电子转移过程，有效调节反应中间体的吸附强度。
