Surface regulated Ni nanoparticles on N-doped mesoporous carbon as an efficient electrocatalyst for CO_(2)reduction  

N,O共修饰的Ni纳米颗粒/氮掺杂介孔碳CO_(2)高效电还原催化剂

作　　者：Min Wang Qi Xie Huimin Chen Guangbo Liu Xuejing Cui Luhua Jiang 王敏;解琦;陈会敏;刘光波;崔学晶;姜鲁华(青岛科技大学材料科学与工程学院纳米材料与电催化实验室,山东青岛266042)

机构地区：[1]Nanomaterials and Electrocatalysis Laboratory,College of Materials and Engineering,Qingdao University of Science and Technology,Qingdao 266042,Shandong,China

出　　处：《Chinese Journal of Catalysis》2021年第12期2306-2312,共7页催化学报（英文）

基　　金：山东省泰山学者项目(ts201712046);山东省重点研发项目(2019JZZY010905);山东省自然科学基金(ZR2020MB025).

摘　　要：Low cost,highly selective and efficient electrocatalysts for CO_(2)reduction reaction(CO_(2)RR)is crucial for lowering the global carbon footprint and mitigating energy shortages.Here,we first report a highly selective and efficient electrocatalyst for CO_(2)RR to CO using a surface-regulated Ni nanoparticles supported on N-doped CMK-3(N,O-Ni/CMK3).Compared with most Ni metal catalysts previously reported with severe competitive hydrogen evolution during the CO_(2)RR,the N,O-Ni/CMK3 catalyst presents a superior CO faradaic efficiency of about 97%,a high CO partial current density(13.01 mA cm^(-1))and turnover frequency(4.25 s^(–1)).The comprehensive characterization provides evidence that the N,O co-regulated Ni acts as the active center.Taking advantage of the N,O co-regulated chemical environment,N,O-Ni/CMK3 also displays a decent stability at negative potentials.Our work paves a novel approach for developing transition metal catalysts for CO_(2)RR with enhanced activity and selectivity via regulating surface chemical environment.利用可再生电力能源将CO_(2)电还原(CO_(2)RR)为高附加值燃料和化学品(CO、甲酸盐和碳氢化合物等)是一种高效、绿色的CO_(2)资源化利用新技术.然而,由于CO_(2)分子中双键难以活化,且存在析氢竞争反应,即使对于CO_(2)电还原为CO这一简单反应,除少数贵金属(Au、Ag和Pd及其合金)外,当前大多数电催化剂对产物CO的选择性和活性仍较低.因此,开发高效、稳定且廉价的CO_(2)RR催化剂具有重要意义.过渡金属Ni储量高、成本低,是潜在的CO_(2)RR催化剂.然而,受限于Ni对*H及*CO等中间物种相对强的吸附能力,Ni基催化剂催化生成产物CO的活性和选择性较低.近年来研究表明,通过对Ni基材料进行表面修饰,可以调控Ni表面与中间物种的吸附强度,从而有效提升Ni基催化剂对CO_(2)RR反应的活性和选择性.鉴于此,本文通过N,O共调控的策略对负载于N掺杂介孔碳上的Ni纳米颗粒进行表面修饰,制得的N,O-Ni/CMK3催化剂能够高效、高选择性地将CO_(2)电还原为CO.X射线衍射、高角度环形暗场扫描透射电子显微镜和X射线光电子能谱等表征结果表明,N,O-Ni/CMK3中的Ni纳米颗粒由金属Ni核和N掺杂的NiO壳组成,即Ni纳米颗粒表面被N,O共调控,这种独特的表面使其表现出与金属Ni不同的CO_(2)RR催化性能.电化学测试结果表明,在0.5 M KHCO_(3)电解液中,N,O-Ni/CMK3催化剂表现出较好的选择性(生成CO法拉第效率达97%)、活性(CO分电流密度为13.01 mA cm^(‒1))和转换频率(4.25 s^(‒1)).表征结果表明,N,O共同调控的Ni是该催化反应的活性中心.此外,得益于N,O共调控的Ni表面,N,O-Ni/CMK3催化剂比O调控的Ni催化剂具有更好的电化学稳定性.本文通过调节Ni催化剂的表面化学环境来调控催化剂与反应中间物种的吸附强度,显著提高了Ni基催化剂对CO_(2)RR反应的催化活性和CO选择性,为开发高活性、高选择性的过渡金属催化剂提供了新思路.

关 键 词：CO_(2)electro-reduction reaction Ni nanoparticle N-doped mesoporous carbon Surface regulation High selectivity 

分 类 号：TQ072[化学工程] TQ426