Geng Wenhao, Chen Wei, Li Guihua, Dong Xiao, Song Yanfang, Wei Wei, Sun Yuhan
CAS Key Laboratory of Low-Carbon Conversion Science and Engineering Shanghai Advanced Research Institute, Chinese Academy of Sciences, 100 Haike Road, Shanghai, 201210, P.R. China.
University of the Chinese Academy of Sciences, Beijing, 100049, China.
ChemSusChem. 2020 Aug 21;13(16):4035-4040. doi: 10.1002/cssc.202001310. Epub 2020 Jul 23.
Metal-organic frameworks (MOFs), combining the advantages of heterogeneous and homogeneous components, have been explored as catalytic materials for the CO electroreduction reaction (CO ERR). However, the unmatched metal nodes result in MOFs having lower faradaic efficiencies (FEs) and limited current densities in CO ERR. Herein, we report a general strategy to promote activities of MOFs via node doping in CO ERR. With ion exchange, an active tin node was doped into zeolitic imidazolate framework-8 (ZIF-8) to facilitate the reduction kinetics of CO . The divalent Sn node accelerates the formation of formic acid (HCOOH), resulting in the highest HCOOH FE of 74 % and total current density (J ) of 27 mA/cm at -1.1 V (vs. reversible hydrogen electrode, RHE) over 0.6 wt% Sn-doped ZIF-8 with stable catalytic performance after seven reuse cycles, which is clearly better compared to the catalytic properties of pristine ZIF-8 (FE =0 %, J =13 mA/cm ). This work opens an avenue for promoting the CO ERR performance of MOFs by node doping.
金属有机框架材料（MOFs）兼具多相和均相成分的优点，已被探索用作二氧化碳电还原反应（CO ERR）的催化材料。然而，不匹配的金属节点导致MOFs在CO ERR中具有较低的法拉第效率（FEs）和有限的电流密度。在此，我们报道了一种通过在CO ERR中进行节点掺杂来提高MOFs活性的通用策略。通过离子交换，将活性锡节点掺杂到沸石咪唑酯骨架-8（ZIF-8）中，以促进CO的还原动力学。二价锡节点加速了甲酸（HCOOH）的形成，在-1.1 V（相对于可逆氢电极，RHE）下，0.6 wt%锡掺杂的ZIF-8上甲酸的法拉第效率最高可达74%，总电流密度（J）为27 mA/cm²，经过七个循环的重复使用后仍具有稳定的催化性能，这明显优于原始ZIF-8的催化性能（FE = 0%，J = 13 mA/cm²）。这项工作为通过节点掺杂提高MOFs的CO ERR性能开辟了一条途径。
