| NH4Cl辅助热解制备镍-氮-碳纳米管催化剂及其电还原CO2性能 |
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| 引用本文： | 吴诗德,易峰,平丹,张逸飞,郝健,刘国际,方少明. NH4Cl辅助热解制备镍-氮-碳纳米管催化剂及其电还原CO2性能[J]. 化工学报, 2022, 73(10): 4484-4497. DOI: 10.11949/0438-1157.20220507 |
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| 作者姓名： | 吴诗德 易峰 平丹 张逸飞 郝健 刘国际 方少明 |
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| 作者单位： | 1.郑州大学化工学院，河南 郑州 450001;2.郑州轻工业大学材料与化学工程学院，河南 郑州 450002;3.省部共建煤炭高效利用与绿色化工国家重点实验室，宁夏 银川 750021 |
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| 基金项目： | 郑州轻工业大学星空众创空间孵化项目(2020ZCKJ218);郑州轻工业大学博士基金项目(2018BSJJ024);河南省自然科学基金项目(212300410299);省部共建煤炭高效利用与绿色化工国家重点实验室开放课题项目(2022-K14);国家自然科学基金-河南联合基金重点项目(U1704256) |
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| 摘 要： | 二氧化碳（CO2）的资源化利用是实现“碳达峰，碳中和”的重要手段。在众多CO2转化技术当中，电催化CO2还原反应因反应条件温和、工艺过程简单等优点，被认为是极具应用前景的减碳技术之一，其关键在于高效、高稳定性电催化剂的开发。过渡金属-氮-碳（M-N-C）材料是电还原CO2生成CO的有效催化剂，针对其高温热解制备过程中活性金属原子容易聚集且氮原子流失严重，进而使得活性位密度降低，催化性能下降等问题，本文提出以双氰胺（DCDA）为碳源和氮源，以乙酰丙酮镍（Ni（acac）2）为金属源，以氯化铵（NH4Cl）为第二氮源和造孔剂，采用简单的NH4Cl辅助热解-酸刻蚀的方法制备得到镍-氮-碳纳米管（Ni-N-CNTs）电还原CO2催化剂，并详细考察NH4Cl添加量对催化剂结构和催化性能的影响。表征结果表明：NH4Cl的加入有利于催化剂纳米管状形貌和多级孔结构的生成，同时有利于催化剂中Ni-Nx （1.6%，摩尔分数）和pyridinic-N （1.75%，摩尔分数）物种含量的增加。一系列性能测试结果表明：催化剂的活性中心为Ni-Nx，同时pyridinic-N的存在也有利于催化性能的提高，当前体中NH4Cl加入量与氮源和金属源总质量比为1∶1时，所得Ni-N-CNTs-1催化剂催化性能最好，在电压为-0.65 V （vs RHE）时，CO法拉第效率最高达92%，此时CO部分电流密度为8 mA·cm-2。此外，该催化剂还表现出良好的催化稳定性，连续恒电位电解12 h，催化性能基本不变。该催化剂制备工艺简单，制备条件可控，研究结果可为高效M-N-C电还原CO2催化剂的设计和制备提供一种切实有效的研究思路和方法。
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| 关 键 词： | 热解 氮掺杂碳纳米管 电还原二氧化碳 |
| 收稿时间： | 2022-04-07 |
NH4Cl assisted preparation of Ni-N-CNTs catalyst and its performance for electrochemical CO2 reduction |
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| Shide WU,Feng YI,Dan PING,Yifei ZHANG,Jian HAO,Guoji LIU,Shaoming FANG. NH4Cl assisted preparation of Ni-N-CNTs catalyst and its performance for electrochemical CO2 reduction[J]. Journal of Chemical Industry and Engineering(China), 2022, 73(10): 4484-4497. DOI: 10.11949/0438-1157.20220507 |
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| Authors: | Shide WU Feng YI Dan PING Yifei ZHANG Jian HAO Guoji LIU Shaoming FANG |
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| Affiliation: | 1.School of Chemical Engineering, Zhengzhou University, Zhengzhou 450001，Henan, China;2.School of Material and Chemical Engineering, Zhengzhou University of Light Industry, Zhengzhou 450002, Henan, China;3.State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering, Yinchuan 750021, Ningxia, China |
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| Abstract: | The resource utilization of carbon dioxide (CO2) is an important means to achieve “carbon peak, carbon neutrality”. Among various CO2 conversion technologies, electrochemical CO2 reduction is considered to be one of the most promising carbon reduction technologies due to its mild reaction conditions and simple process. The key lies in the development of high-efficiency and high-stability electrocatalysts. Transition metal-nitrogen-carbon (M-N-C) material is an effective catalyst for electrochemical CO2 reduction to CO. However, the inevitable aggregation of active metal atoms and the serious N loss during the pyrolysis preparation usually lead to the reduction of active sites density and then the degradation of catalytic performance. Herein, this paper proposes the construction of Ni-N-carbon nanotubes (Ni-N-CNTs) catalysts for electrochemical CO2 reduction via NH4Cl-assisted pyrolysis and associated acid leaching method. The catalysts are prepared by using dicyandiamide as carbon and nitrogen sources, the nickel acetylacetonate as metal source and the NH4Cl as additional nitrogen source and pore-forming agent. The influence of NH4Cl addition on the structure and catalytic performance of catalysts is investigated in detail. The characterization results show that the addition of NH4Cl is beneficial to the formation of nanotube-like morphology and hierarchical pore structure of the catalyst. At the same time, it is beneficial to increase the content of Ni-Nx (1.6%, mole fraction) and pyridinic-N (1.75%, mole fraction) species in the catalyst. A series of catalytic performance results indicate that the catalyst active site is the atomic Ni-Nx, and the presence of pyridinic-N species also contribute to an enhanced catalytic performance. When the mass ratio of NH4Cl to the total mass of nitrogen and metal sources is 1∶1, the derived Ni-N-CNTs-1 catalyst exhibits the best catalytic performance. The CO Faradaic efficiency is as high as 92% with a large CO partial current density of 8 mA·cm-2 at a low potential of -0.65 V (vs RHE). In addition, this catalyst also shows good operation stability for 12 h without obvious performance decay. The catalyst preparation process is simple and the preparation conditions are controllable. This work will provide a practical and feasible approach to build highly efficient M-N-C catalyst for CO2 electroreduction. |
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| Keywords: | pyrolysis N doped carbon nanotubes electrochemical CO2 reduction |
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