Active sites and reaction mechanism for N-doped carbocatalysis of phenol removal
Mingjie Zhang, Han Chen, Wenyao Chen, Wei Luo, Yueqiang Cao, Gang Qian, Xinggui Zhou, Xiaoguang Duan, Xiaoguang Duan, Shaobin Wang, Xuezhi Duan, Xuezhi Duan
Abstract
Heteroatom-doping of carbocatalysts has been a powerful strategy to remarkably enhance the catalytic performance. Herein, the underlying nature of N promotional effects on peroxymonosulfate (PMS) activation for phenol removal is understood by combining kinetics analysis with multiple techniques. A strategy using mixed acid oxidation of carbon nanotube (CNT) followed by NH3 treatment is employed to yield a series of catalysts with different N-doping contents but similar fraction of sp2-hybridized carbon and defective degree, endowing with a chance to discriminate the dominant N-containing active sites. The multi-sites kinetics analysis suggests the graphitic N-containing sites as the dominant active sites. The mechanism of the surface-bound reactive species is also discriminated as the dominant reaction mechanism. The insights reported here could provide the methodology to fundamentally understand the heteroatom-doping effects of carbocatalysis.