Abstract: In response to the challenge of poor stability and rapid deactivation of the active phase in residue hydrotreating catalysts during reaction processes,the carbon-coated active phase structure was prepared using ethylene tar as the carbon source, and the carbon-coated active phasewas characterized by means of X-ray diffraction, Raman spectroscopy, and Fourier transform infrared spectroscopy, etc. The study explores the effects of carbon source, carbon content,and calcination temperature on the structure of the carbon layer and the hydrodesulfurization and microcarbon residue reduction activities of the carbon-coated catalyst. The studies show that ethylene tar is more suitable than 1-methylnaphthalene as a carbon source for preparing carbon layer structures, and the carbon layer prepared from it has a higher degree of condensation. With the increase of carbon content and calcination temperature, the degree of graphitization of the carbon layer improves. The carbon layer structure inevitably covers the active sites of the catalyst, reducing both the hydrodesulfurization and microcarbon residue reduction activities of the catalyst. However, the coated carbon structure can solve the problem of active phase degradation during the reaction process and enhance the stability of the active phase structure, which is of great significance for improving the stability of catalyst activity.

Key words: carbon coating, active phase structure, RDS, ethylene tar, graphitization, calcination temperature