Insight into the effect of non-stoichiometric sulfur on a NiMoS hydrodesulfurization catalyst. Issue 2 (27th August 2015)

• Record Type: Journal Article
• Authors: Lai, Weikun; Xu, Yingrui; Ren, Yuhong; Yang, Lefu; Zheng, Jinbao; Yi, Xiaodong; Fang, Weiping
• Is Part Of: Catalysis science & technology. Volume 6:Issue 2(2016)
• Page Start: 497
• Page End: 506
• Publication Date: 2015-08-27
• Subjects: Catalysis -- Periodicals; 541.395
• DOI: 10.1039/c5cy01142f
• Languages: English
• ISSNs: 2044-4753

Abstract

Abstract : A sulfur dynamic equilibrium between the NiMoS edge and the gas phase which determines the number of CUS, SH groups and HDS activity is elucidated. Abstract : The findings in this study provide new insight into the NiMoS model, revealing that there is a sulfur dynamic equilibrium between the NiMoS edge and the gas phase. Since the evolution of non-stoichiometric sulfur proceeds rapidly at the initial stage of hydrodesulfurization reaction, the sulfur dynamic equilibrium does not draw so much attention. The results indicate that excess sulfur on the Ni–Mo–S edge can be reduced by hydrogen to form SH groups and release H2 S, which lead to a low sulfur-covered NiMoS edge and a significant increase in coordinatively unsaturated sites (CUS), resulting in an outstanding HDS activity. Apart from elucidating the effect of non-stoichiometric sulfur on the NiMoS structure, the relationship among H2 S partial pressure, S x and HDS activity has been quantitatively studied. It is expected that these results will be used to deepen the understanding of HDS reaction over promoted MoS2 catalysts, as well as to guide the research on ultra-deep HDS of fuel oils.