物理化学学报

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富氮空心蠕虫状碳材料的合成及其苯甲醇非金属选择性催化氧化的高活性

安平1, 付宇2, 韦丹蕾1, 郭杨龙2, 詹望成2, 张金水1   

  1. 1 福州大学化学学院, 能源与环境光催化国家重点实验室, 福州 350108;
    2 华东理工大学化学与分子工程学院, 工业催化研究所, 上海 200237
  • 收稿日期:2020-01-07 修回日期:2020-02-10 录用日期:2020-02-26 发布日期:2020-02-28
  • 通讯作者: 张金水, 詹望成 E-mail:jinshui.zhang@fzu.edu.cn;zhanwc@ecust.edu.cn
  • 基金资助:
    国家自然科学基金(21972022,U1805255),111项目(D16008),福建省自然科学基金(2018J01681)和能源与环境光催化国家重点实验室自主研究项目(SKLPEE-2017A03)资助项目

Hollow Nitrogen-Rich Carbon Nanoworms with High Activity for Metal-Free Selective Aerobic Oxidation of Benzyl Alcohol

Ping An1, Yu Fu2, Danlei Wei1, Yanglong Guo2, Wangcheng Zhan2, Jinshui Zhang1   

  1. 1 State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou 350108, P. R. China;
    2 Key Laboratory for Advanced Materials and Research Institute of Industrial Catalysis, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, P. R. China
  • Received:2020-01-07 Revised:2020-02-10 Accepted:2020-02-26 Published:2020-02-28
  • Supported by:
    The project was supported by the National Natural Science Foundation of China (21972022, U1805255), the 111 Project (D16008), Natural Science Foundation of Fujian Province, China (2018J01681), and the Independent Research Project of State Key Laboratory of Photocatalysis on Energy and Environment (SKLPEE-2017A03).

摘要: 作为非金属催化材料的典型代表,碳材料已经成为催化领域的研究热点之一。本文采用石墨化氮化碳(g-C3N4)为硬模板,通过先包覆树脂后碳化的简便方法合成中空碳材料(h-NCNW)。采用X射线衍射(XRD)、高分辨率透射电子显微镜(HR-TEM)、N2吸附-脱附、傅立叶变换红外光谱(FT-IR)、热重(TG)、拉曼光谱和X射线光电子能谱(XPS)对h-NCNWs碳材料进行表征,并且研究了h-NCNWs催化剂对O2选择性氧化苯甲醇的催化活性。结果表明,通过在g-C3N4纳米片外围包覆由间苯二酚和甲醛前驱体缩合形成的薄层树脂,并在惰性气氛下进行高温热处理,去除g-C3N4硬模板,最终得到富氮(9.83%)空心蠕虫状碳材料,并且可通过改变制备过程中间苯二酚与g-C3N4的相对比例来调整氮含量和壳厚度。在h-NCNW中,杂原子N主要以石墨型和吡啶型的形式化学地结合到碳骨架中,其中石墨型N占主导地位,使得该材料在苯甲醇氧化反应中表现优异的催化活性。在120℃时,采用间苯二酚与g-C3N4质量比为0.5制备的h-NCNWs催化剂,苯甲醇转化率为24.9%,苯甲醛选择性> 99%。但是N掺杂量会显著影响h-NCNWs催化剂的催化活性,采用间苯二酚与g-C3N4质量比为1.5制备的h-NCNWs催化剂,苯甲醇转化率降低至13.1%。另一方面,h-NCNWs催化剂在反应过程中显示出优异的稳定性,在五次循环使用过程中催化剂的活性保持不变。综上所述,理性设计和合成的碳材料作为多相氧化反应的催化剂具有巨大的潜力。

关键词: 中空纳米结构, N掺杂, 非金属催化剂, 选择氧化, 苯甲醇

Abstract: Carbon materials have become one of the research hotspots in the field of catalysis as a typical representative of non-metallic catalytic materials. Herein, a facile synthetic strategy is developed to fabricate a series of hollow carbon nanoworms (h-NCNWs) that contain nitrogen up to 9.83 wt% by employing graphitic carbon nitride (g-C3N4) as the sacrificing template and solid nitrogen source. The h-NCNWs catalysts were characterized by X-ray diffraction (XRD), high-resolution transmission electron microscope (HR-TEM), N2 adsorption-desorption, Fourier transform infrared spectroscopy (FT-IR), thermal gravimetric (TG), Raman spectra, and X-ray photoelectron spectroscopies (XPS). The catalytic activities of the h-NCNWs catalysts for selective oxidation of benzyl alcohol with O2 were also evaluated. The characterization results revealed that the h-NCNWs catalysts displayed a unique hollow worm-like nanostructure with turbostratic carbon shells. The nitrogen content and shell thickness can be tuned by varying the relative ratio of resorcinol to g-C3N4 during the preparation process. Furthermore, nitrogen is incorporated to the carbon network in the form of graphite (predominantly) and pyridine, which is critical for the enhancement of the catalytic activity of carbon catalysts for the selective oxidation of benzyl alcohol. At a reaction temperature of 120℃, a 24.9% conversion of benzyl alcohol with >99% selectivity to benzaldehyde can be achieved on the h-NCNWs catalyst prepared with a mass ratio of resorcinol to g-C3N4 of 0.5. However, the catalytic activities of the h-NCNWs catalysts were dependent on the amount of N dopants, in particular graphitic nitrogen species. The conversion of benzyl alcohol markedly decreased to 13.1% on the h-NCNWs catalyst prepared with a mass ratio of resorcinol to g-C3N4 of 1.5. Moreover, the h-NCNWs catalyst showed excellent stability during the reaction process. The conversion of benzyl alcohol and the high selectivity to aldehyde can be kept within five catalytic runs over the h-NCNWs0.5 catalyst. These results indicate that rationally designed carbon materials have great potential as highly efficient heterogeneous catalysts for oxidation reactions.

Key words: Hollow nanostructure, Nitrogen doping, Metal-free catalyst, Selective oxidation, Benzyl alcohol

MSC2000: 

  • O643