摘要
二氧化碳电还原有利于二氧化碳高价值利用和间歇性电能的存储,是一种极具应用前景的新技术.自支撑催化剂比粉末催化剂在构建电极方面具有明显优势,但缺乏有效的合成方法.本研究采用电纺丝-碳化法合成了一种自支撑的BiCu/碳杂化纳米纤维膜(BiCu/CHNM),可直接用作工作电极在流动池中将二氧化碳还原为甲酸盐,其法拉第效率为87.67%,分电流密度为142.9 mA cm^(-2).稳定性测试中,甲酸盐的法拉第效率在高偏电流密度(>100 mA cm^(-2))下可在50小时内连续保持在80%以上.原位拉曼光谱和密度泛函理论计算证实,铜掺杂降低了Bi(012)平面上HCOO~-形成的能垒,同时提高了碳纳米纤维网络的导电性.由于同时具有高导电框架结构和高度分散的BiCu活性位点,这种杂化膜同时表现出高活性、高选择性和长时间稳定性.
CO_(2) electroreduction is an alluring technology for high-value CO_(2) utilization and intermittent electrical energy storage. Self-supporting catalysts with high efficiency have clear advantages over powder ones in electrode construction but still lack effective synthesis methods. In this work, a self-supporting BiCu/carbon hybrid nanofiber membrane(BiCu/CHNM) was synthesized by electrospinning-calcination and employed directly as a working electrode in a flow cell for CO_(2) electroreduction to formate with a high Faradaic efficiency of 87.67% at a partial current density of 142.9 mA cm^(-2). In stability tests, the Faradaic efficiency of formate remained at 80% for 50 h at high partial current densities(>100 mA cm^(-2)). In-situ Raman spectra and density functional theory calculations confirmed that copper doping lowers the energy barrier of HCOO-formation on the Bi(012)plane and increases the conductivity of the carbon nanofiber network. Due to the well-designed conductive framework and the highly dispersed BiCu active sites, this hybrid membrane shows high activity, high selectivity, and long stability simultaneously.
作者
宋德文
张世鹏
宁汇
费翔
汪明旺
王小珊
吴文婷
赵青山
李永哲
吴明铂
Dewen Song;Shipeng Zhang;Hui Ning;Xiang Fei;Mingwang Wang;Xiaoshan Wang;Wenting Wu;Qingshan Zhao;Yongzhe Li;Mingbo Wu(State Key Laboratory of Heavy Oil Processing,College of Chemical Engineering,College of New Energy,Institute of New Energy,China University of Petroleum(East China),Qingdao 266580,China;Shandong Dongyue Future Hydrogen Energy Material Co.,Ltd,Zibo 256412,China)
基金
supported by the National Natural Science Foundation of China (52072409)
the Major Scientific and Technological Innovation Project of Shandong Province (2020CXGC010403)
Taishan Scholar Project of Shandong Province of China (ts201712020)。
