ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Preparation of graphitic carbon nitride g-C₃N₄-HMCM-22 composite catalysts and enhanced para-selectivity in m-xylene isomerization

Zonghui Liu, Zhongze Zhang, Dehua Xie, Xiaotian Guan, Fei Wang, and Bing Xue

Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou, People’s Republic of China

E-mail: liuzh@cczu.edu.cn

Received: 31 May 2021  Accepted: 11 November 2021

Abstract:

A series of novel graphitic carbon nitride g-C₃N₄-HMCM-22 composite catalysts were successfully prepared. Their structure and acid properties were well characterized by thermogravimetric analysis (TGA), X-ray diffraction (XRD), N₂ adsorption–desorption, Fourier transform infrared spectroscopy (TFIR), X-ray photoelectron spectroscopy (XPS), Scanning Electron Microscopy (SEM), and Py-FTIR. The prepared g-C₃N₄-HMCM-22 composite catalysts were then used for m-xylene (MX) isomerization. The effect of introduction of g-C₃N₄ on catalytic performance was studied. Compared with parent HMCM-22 catalyst, g-C₃N₄-HMCM-22 composite catalysts exhibited an improved p-xylene (PX) selectivity in MX isomerization. Moreover, G1H1 composite catalyst showed the highest PX selectivity than other as-prepared composite samples. Correlating the catalyst performance with its physical and chemical properties uncovers that increasing amounts of Lewis acid sites and effectively inhibiting the external Brönsted acid sites of HMCM-22 would be the key to improving the selectivity of PX.

Keywords: m-xylene; p-xylene; Isomerization; g-C3N4-HMCM-22 catalyst

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-021-01982-4

Chemical Papers 76 (3) 1875–1884 (2022)