催化学报 ›› 2023, Vol. 50: 314-323.DOI: 10.1016/S1872-2067(23)64455-9

• 论文 • 上一篇    下一篇

GaN/In2O3的界面工程用于高效电催化CO2还原制备甲酸

李轩a, 蒋兴星b, 孔艳a, 孙建桔b, 胡琪b, 柴晓燕b,*(), 杨恒攀b,*(), 何传新b,*()   

  1. a中国科学技术大学化学物理系, 安徽合肥 230026
    b深圳大学化学与环境工程学院, 广东深圳 518060
  • 收稿日期:2023-03-24 接受日期:2023-05-17 出版日期:2023-07-18 发布日期:2023-07-25
  • 通讯作者: *电子信箱: chaixy@szu.edu.cn (柴晓燕), hpyang@szu.edu.cn (杨恒攀), hecx@szu.edu.cn (何传新).
  • 基金资助:
    深圳市科技计划项目(JCYJ20190808150001775);深圳市科技计划项目(RCBS20200714114819161);深圳市科技计划项目(JCYJ20190808111801674);深圳市科技计划项目(SGDX20201103095802006);广东省基础与应用基础研究基金项目(2023A1515012776);国家自然科学基金项目(22172099);国家自然科学基金项目(U21A20312)

Interface engineering of a GaN/In2O3 heterostructure for highly efficient electrocatalytic CO2 reduction to formate

Xuan Lia, Xingxing Jiangb, Yan Konga, Jianju Sunb, Qi Hub, Xiaoyan Chaib,*(), Hengpan Yangb,*(), Chuanxin Heb,*()   

  1. aDepartment of Chemical Physics, University of Science and Technology of China, Hefei 230026, Anhui, China
    bShenzhen Key Laboratory for Functional Polymer, College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, Guangdong, China
  • Received:2023-03-24 Accepted:2023-05-17 Online:2023-07-18 Published:2023-07-25
  • Contact: *E-mail: chaixy@szu.edu.cn (X. Chai), hpyang@szu.edu.cn (H. Yang), hecx@szu.edu.cn (C. He).
  • Supported by:
    Shenzhen Science and Technology Program(JCYJ20190808150001775);Shenzhen Science and Technology Program(RCBS20200714114819161);Shenzhen Science and Technology Program(JCYJ20190808111801674);Shenzhen Science and Technology Program(SGDX20201103095802006);Guangdong Basic and Applied Basic Research Foundation(2023A1515012776);National Natural Science Foundation of China(22172099);National Natural Science Foundation of China(U21A20312)

摘要:

随着碳中和、碳达峰理念和可持续发展目标的深入贯彻, 寻求一种新的科学技术将化石燃料燃烧产生的大量二氧化碳转化成具有高经济价值的化工产品是目前的研究热点. 这不仅能够消耗二氧化碳气体, 而且能够在一定程度上缓解能源危机. 其中, 电催化二氧化碳还原是一种潜力巨大的转化技术, 其仅需消耗电能就可以将二氧化碳转化成高附加值产物. 然而, 由于二氧化碳分子具有高化学惰性, 需要消耗大量能量使其转化. 同时, 该反应产物种类复杂, 需要设计开发一种催化剂来降低反应能垒和提高单一产物的选择性. 铟(In)作为一种无毒的金属物种, 表现出较高的电催化二氧化碳还原制备甲酸活性, 但是其法拉第效率和稳定性有待进一步提升.

本文采用静电纺丝和相分离方法设计合成了一种富缺陷的GaN/In2O3界面型催化剂(GaN/In2O3@PCNF), 并将其用于电催化二氧化碳还原制备甲酸. 在焙烧过程中, ZIF-8前驱体中Zn原子的蒸发促进了Ga原子与N原子的结合, 并引发共晶镓铟(EGaIn)分离成GaN和In2O3界面. 透射电子显微镜和X射线光电子能谱结果证实了界面的生成以及界面对于In 3d轨道的电子调控. 电催化二氧化碳还原的电化学测试结果表明, 催化剂在-0.9 VRHE的电位下实现了87%的甲酸法拉第效率以及29.7 mA cm‒2的分电流密度. 同时, 催化剂表现出30 h的稳定性, 且甲酸的法拉第效率未明显下降. 该催化剂较好的性能和稳定性可以归结为以下原因: (1)界面的电子结构调控, 优化了In2O3的电子结构; (2)较低的塔菲尔斜率带来了较快的电子转移速度; (3)多孔的碳纳米纤维促进了活性位点的充分暴露, 碳包封和GaN的锚定作用使催化剂具有较好的稳定性. 原位拉曼测试和密度泛函理论计算进一步揭示了界面的存在能够降低甲酸含氧中间体的吸附能, 从而有利于二氧化碳还原制备甲酸. 综上, 本文为电催化二氧化碳还原的界面型催化剂提供了一种新的设计策略.

关键词: 电催化二氧化碳还原, 界面, 甲酸, 共晶镓铟, 氧化铟

Abstract:

Electrocatalytic CO2 reduction reaction (eCO2RR) to obtain formate is a promising method to consume CO2 and alleviate the energy crisis. Indium-based electrocatalysts have demonstrated considerable potential to produce formate. However, their unsatisfactory long-term stability and selectivity restrict their widespread application. In this study, a heterostructure of GaN- and In2O3-encapsulated porous carbon nanofibers was constructed via electrospinning and the phase transition of eutectic gallium-indium during calcination. The GaN and In2O3 nanoparticle-encapsulated porous carbon nanofibers, when used as electrocatalysts for eCO2RR, displayed high formate selectivity with a faradaic efficiency of 87% and maximum partial current density of 29.7 mA cm-2 in a 0.5 mol L-1 KHCO3 aqueous solution. The existence of the interface can cause a positive shift in the In 3d binding energy, leading to electronic redistribution. Moreover, the GaN component induced a higher proportion of O-vacancy sites in the In2O3 phase, resulting in improved selectivity for CO2-to-formate. In-situ Raman experiments and density functional theory calculations revealed that the interface between GaN and In2O3 could lower the adsorption energy of the key intermediates for formate production, thus providing superior eCO2RR performance. In addition, the framework of the porous carbon nanofibers exhibited a large electrochemically active surface area, which enabled the full exposure of the active sites. This study highlights the cooperation between GaN and In2O3 components and provides new insights into the rational design of catalysts with high CO2-to-formate conversion efficiencies.

Key words: Electrocatalytic CO2 reduction reaction, Interface, Formate, Eutectic gallium-indium, In2O3