Effect of Support Treatment on Hydrodenitrogenation Performance for Pyrolysis Gasoline over Mo/Al2O3 Catalysts
WANG Jian, ZHU Junhua, YE Yingchun, WANG Wanmin, CHEN Liangfeng, YANG Weimin
SINOPEC Shanghai Research Institute of Petrochemical Technology Company Limited, State Key Laboratory of Green Chemical Engineering and Industrial Catalysis, Shanghai 201208, China
Abstract：The deterioration of feedstock for ethylene production has led to a remarkable increase in nitrogen content in pyrolysis gasoline (py-gas). Developing novel hydrodenitrogenation (HDN) catalysts is therefore of great significance to process py-gas with higher nitrogen content. In this paper, we adopted commonly used Mo/Al2O3 as model catalyst, and via various support treatment we have successfully manipulated catalysts structural properties. Catalysts were characterized by various techniques, including X-ray diffraction (XRD), H2-temperature programmed reduction (H2-TPR), High-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS) and Pyridine-Fourier transform infrared spectroscopy (Py-IR). We systematically investigated the effects of support treatment on structural properties of Mo/Al2O3 catalysts and their HDN performance for py-gas. The results showed that for all Mo/Al2O3 samples, MoS2 active species were well-dispersed in mono-layer state on Al2O3 support for catalysts with and without support treatment. Citric acid and ammonia treatment could effectively modulate surface acidity and active sites-support interaction, which finally affected sulfurization of molybdenum species as well as surface S/Mo molar ratio. It was also revealed that pyridine HDN was governed by hydrogenation (HYD) and C—N hydrogenolysis (CNH) processes, which was, under lower pyridine conversion condition (less than 20%), HDN performance was mainly related with unsaturated coordination sites (CUS) amount, and under higher pyridine conversion condition (approximately 50%), HDN performance could be well-interpreted by CUS amount and Br?nsted acid (B acid) property, catalyst after support alkali-treatment with proper surface S/Mo molar ratio and B acidity showed superior HDN activity. Above all, these results provide us important guidance for research and development of Mo-based HDN catalysts.
WANG Jian,ZHU Junhua,YE Yingchun et al. Effect of Support Treatment on Hydrodenitrogenation Performance for Pyrolysis Gasoline over Mo/Al2O3 Catalysts[J]. Chemical Reaction Engineering and Technology, 2023, 39(4): 306-312.
