Influence of doping nitrogen on the catalytic performance of carbon nanotubes encapsulating cobalt for selective oxidation of arylalkanes (Open Access)--颗粒学报PARTICUOLOGY

Xiang, G., Wang, X., Zhang, L., & Liu, Z. (2021). Influence of doping nitrogen on the catalytic performance of carbon nanotubes encapsulating cobalt for selective oxidation of arylalkanes. Particuology, 58, 85-91. https://doi.org/10.1016/j.partic.2021.02.002

Influence of doping nitrogen on the catalytic performance of carbon nanotubes encapsulating cobalt for selective oxidation of arylalkanes (Open Access)

Ganghua Xiang, Xiaocan Wang, Lushuang Zhang, Zhigang Liu ^*

Advanced Catalytic Engineering Research Center of the Ministry of Education, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, Hunan, China

10.1016/j.partic.2021.02.002

Volume 58, October 2021, Pages 85-91

Received 4 January 2021, Revised 7 February 2021, Accepted 13 February 2021, Available online 18 March 2021, Version of Record 31 March 2021.

E-mail: liuzhigang@hnu.edu.cn

Highlights

• N-doped carbon nanotubes with encapsulated Co (NCNTs-X) are prepared by pyrolysis.

• NCNTs-X shows high catalytic performance for selective oxidation of arylalkanes.

• The relationship between the nitrogen content and the generation of NCNTs is discussed.

• The synergistic effect of Co–N_x sites is responsible for the catalytic performance.

Abstract

Efficient selective oxidation of hydrocarbons to corresponding ketones has been a significant but challenging work in the past decades. Here, a nitrogen-doped bamboo-like carbon nanotubes encapsulating cobalt catalyst (NCNTs-X) using citric acid, melamine and CoCl₂·6H₂O as precursors was synthesized by a simple pyrolysis method. A series of characterization techniques were employed to investigate the physicochemical properties of samples. And the results show that the as-prepared catalysts achieve a high catalytic performance for selective ethylbenzene oxidation (78.3% ethylbenzene conversion) using molecular oxygen as oxidant, especially giving a high selectivity (93.8% selectivity to acetophenone). According to the investigation of the structure-activity relationship of the catalysts, it can be deduced that the Co–N_x sites have an obvious positive effect on catalytic performance thanks to the synergistic effect between metallic cobalt and pyridinic N.

Graphical abstract

Keywords

Bamboo-like carbon nanotubes; Encapsulation; Co–N_x; Ethylbenzene; Selective oxidation

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