Chalcogen heteroatoms doped nickel-nitrogen-carbon single-atom catalysts with asymmetric coordination for efficient electrochemical CO_(2) reduction  

具有非对称配位结构的硫族杂原子掺杂Ni-N-C单原子催化剂及其电化学二氧化碳还原性能

作　　者：Jialin Wang Kaini Zhang Ta Thi Thuy Ng Yiqing Wang Yuchuan Shi Daixing Wei Chung-Li Dong Shaohua Shen 王佳琳;张凯妮;Ta Thi Thuy Nga;王亦清;石玉川;魏代星;董崇礼;沈少华(西安交通大学能源与动力工程学院,陕西西安710049;淡江大学物理系,中国台湾新北25137)

机构地区：[1]International Research Center for Renewable Energy,State Key Laboratory of Multiphase Flow in Power Engineering,Xi'an Jiaotong University,Xi'an 710049,Shaanxi,China [2]Department of Physics,Tamkang University,New Taipei City 25137,Taiwan,China

出　　处：《Chinese Journal of Catalysis》2024年第9期54-65,共12页催化学报（英文）

基　　金：国家自然科学基金(52225606,52488201).

摘　　要：The electronic configuration of central metal atoms in single-atom catalysts(SACs)is pivotal in electrochemical CO_(2) reduction reaction(eCO_(2)RR).Herein,chalcogen heteroatoms(e.g.,S,Se,and Te)were incorporated into the symmetric nickel-nitrogen-carbon(Ni-N_(4)-C)configuration to obtain Ni-X-N_(3)-C(X:S,Se,and Te)SACs with asymmetric coordination presented for central Ni atoms.Among these obtained Ni-X-N_(3)-C(X:S,Se,and Te)SACs,Ni-Se-N_(3)-C exhibited superior eCO_(2)RR activity,with CO selectivity reaching~98% at-0.70 V versus reversible hydrogen electrode(RHE).The Zn-CO_(2) battery integrated with Ni-Se-N_(3)-C as cathode and Zn foil as anode achieved a peak power density of 1.82 mW cm^(-2) and maintained remarkable rechargeable stability over 20 h.In-situ spectral investigations and theoretical calculations demonstrated that the chalcogen heteroatoms doped into the Ni-N_(4)-C configuration would break coordination symmetry and trigger charge redistribution,and then regulate the intermediate behaviors and thermodynamic reaction pathways for eCO_(2)RR.Especially,for Ni-Se-N_(3)-C,the introduced Se atoms could significantly raise the d-band center of central Ni atoms and thus remarkably lower the energy barrier for the rate-determining step of ^(*)COOH formation,contributing to the promising eCO_(2)RR performance for high selectivity CO production by competing with hydrogen evolution reaction.电化学二氧化碳还原反应(eCO_(2)RR)作为一种能将CO_(2)转化为高附加值碳基燃料的清洁技术,对于实现碳中和具有重要意义.近年来,过渡金属单原子催化剂(M-N-C SACs)因具备出色的稳定性、活性以及较高的原子利用效率,已被广泛认为是用于eCO_(2)RR生产CO中极具潜力的催化剂之一.其中,具有饱和对称配位结构的Ni-N_(4)已被证实是eCO_(2)RR的活性中心.然而,Ni-N_(4)-C SACs中心金属周围对称的几何结构和电子构型导致其在eCO_(2)RR过程中能垒较高.同时,其电催化活性也仍有待提升.为了调控M-N-C SACs中心金属周围电子排布,本文分别使用S粉、Se粉和Te粉作为杂原子源,通过高温焙烧方法将硫族元素(如:S,Se和Te)引入对称的Ni-N_(4)-C构型中,获得具有不对称配位环境和电子结构的Ni-X-N_(3)-C SACs(X:S,Se和Te).球差电镜结果表明成功合成了Ni-X-N_(3)-C单原子催化剂,同步辐射拟合结果证明了SACs中心Ni原子与三个邻近的N原子和一个杂原子(S,Se和Te)成键形成Ni-X-N_(3)-C配位结构.此外,X射线光电子能谱结果表明,随着杂原子(S,Se和Te)的掺杂,Ni2p轨道结合能逐渐降低,说明杂原子与金属Ni成键,导致了中心金属Ni原子周围电荷分布明显变化.配位原子电负性大小顺序依次为:N>S>Se>Te,因此Ni 2p轨道的结合能大小趋势为:Ni-N_(4)-C>Ni-S-N_(3)-C>Ni-Se-N_(3)-C>Ni-Te-N_(3)-C.同步辐射结果表明,与具有标准平面4配位(Ni-N_(4))的酞菁镍(NiPc)相比,Ni-X-N_(3)-C SACs(X代表S,Se和Te)中Ni的边前峰强度明显增大,归因于杂原子的引入导致中心对称结构发生变化.理论计算结果进一步揭示了杂原子的引入会改变中心金属周围的配位环境,诱导电荷重分布,使得Ni原子的d带中心位置更接近费米能级,增强了^(*)COOH中间体在催化剂表面的吸附强度,从而提升了eCO_(2)RR中CO产物选择性.特别是Se掺杂使得Ni原子的d带中心最接近费米能级,从而显著降低了^(*)C

关 键 词：Electrochemical CO_(2) reduction reaction Chalcogen heteroatoms Single-atom catalysts Asymmetric coordination CO production 

分 类 号：O643.36[理学—物理化学]