Abstract:

Metal?nitrogen doped carbon is an emerging class of non?precious metal electrocatalysts used in carbon dioxide reduction reactions(CO₂RR).Metal?nitrogen doped carbon is an emerging class of non?precious metal electrocatalysts in carbon dioxide reduction reactions(CO₂RR).Current preparation methods mainly use impregnation?based post?processing,which often involves multiple preparation steps and limited types of metals.In this work,an iron?copper(FeCu) and nitrogen doped carbon catalyst was prepared through a coordination competition strategy.In the preparation,4,4?bipyridine served as ligand and iron nitrate and copper chloride as metal sites to form FeCu coordination polymers,which was directly transformed into FeCu?nitrogen doped porous carbon catalysts.The physicochemical properties such as morphological structure,metal species state and pore structure were characterized by SEM,TEM,XRD and N₂ adsorption?desorption,respectively.The performance of different FeCu?nitrogen doped carbon catalysts in electrocatalytic CO₂RR to syngas was examined in a three?electrode system.The regulation of n(CO)/n(H₂) in syngas was studied by adjusting the metal composition,metal combination and pyrolysis temperature,etc.The n(CO)/n(H₂) generated in the wide potential range of -0.7 V to -1.3 V can be regulated in the range of 0.15~3.33,which can meet the supply gas ratios for important reactions such as methanol synthesis,Fischer?Tropsch reaction and syngas fermentation.

Key words: Porous carbon, Metal?nitrogen doped carbon, Bimetallic catalysts, Electrocatalytic CO₂ reduction, Syngas

摘要：

金属?氮掺杂炭是一类新兴的应用于CO₂还原反应(CO₂RR)的非贵金属电催化剂。目前的制备方法主要采用浸渍法为主的后处理方式，通常涉及较多的步骤，且金属种类单一。以4,4′?联吡啶为配体、硝酸铁和氯化铜为金属节点，通过配位竞争的策略合成FeCu配位聚合物，后经原位热处理得到FeCu?N?C系列催化剂。分别采用SEM、TEM、XRD、N₂吸附?脱附等技术对催化剂形貌结构、金属物种状态、孔隙结构等进行了表征。采用三电极体系评价了FeCu?N?C系列催化剂在电催化CO₂RR产合成气（CO/H₂）中的性能。结果表明，通过调控Fe、Cu的物质的量比、炭化温度、金属组合等条件可调控合成气中n(CO)/n(H₂)的比例。在较宽电位范围内（-0.7~-1.3 V）生成的合成气中n(CO)/n(H₂)可在0.15~3.33调控，可满足甲醇合成、费托反应及合成气发酵等重要反应的供给气配比。

关键词: 多孔炭, 金属?氮掺杂炭, 双金属催化剂, 电催化CO₂还原, 合成气