N-Doping-Induced Nonradical Reaction on Single-Walled Carbon Nanotubes for Catalytic Phenol Oxidation
N-Doping-Induced Nonradical Reaction on Single-Walled Carbon Nanotubes for Catalytic Phenol Oxidation
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DOI：
10.1021/cs5017613
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发表时间：
2015-02-01
期刊：
影响因子：
12.9
通讯作者：
Wang, Shaobin
中科院分区：
文献类型：
--
作者：
Duan, Xiaoguang;Sun, Hongqi;Wang, Shaobin
无金属材料已被证明是传统金属基催化剂的有前途的替代品。在过氧单硫酸盐（PMS）活化中，已经实现了与钴基或锰基催化剂相当的纳米碳上的催化，但是必须解决催化剂稳定性，并且还需要阐明机理。在这项研究中，N-掺杂的碳纳米管（NoCNTs）作为无金属催化剂的苯酚催化氧化与硫酸根，更重要的是，PMS活化的详细机制和氮杂原子的作用进行了全面的研究。首次发现了氮杂原子掺杂后PMS氧化苯酚反应中伴随自由基生成的非自由基途径（（OH）-O-中心点和SO 4-中心点）。由于新兴的非自由基过程，NoCNTs呈现出优异的稳定性。研究结果可用于设计高效和稳健的无金属催化剂，同时具有上级催化性能和高稳定性，用于各种多相催化过程。
Metal-free materials have been demonstrated to be promising alternatives to conventional metal-based catalysts. Catalysis on nanocarbons comparable to that of cobalt- or manganese-based catalysts in peroxymonosulfate (PMS) activation has been achieved, yet the catalyst stability has to be addressed and the mechanism also needs to be elucidated. In this study, N-doped carbon nanotubes (NoCNTs) were employed as metal-free catalysts for phenol catalytic oxidation with sulfate radicals and, more importantly, a detailed mechanism of PMS activation and the roles of nitrogen heteroatoms were comprehensively investigated. For the first time, a nonradical pathway accompanied by radical generation ((OH)-O-center dot and SO4 center dot-) in phenol oxidation with PMS was discovered upon nitrogen heteroatom doping. The NoCNTs presented excellent stability due to the emerging nonradical processes. The findings can be used for the design of efficient and robust metal-free catalysts with both superior catalytic performance and high stability for various heterogeneous catalytic processes.