Research Progress on Zeolite-Based Metal Sulfide Hydrocracking Catalysts
As an important technology for the production of clean oils including diesel,lubricating oil and jet fuel and chemicals such as naphtha and olefin cracking materials,hydrocracking plays an irreplaceable role in the petrochemical industry.The bifunctional catalysts in the hydrocracking reaction are composed of metal sites and acid sites,and the zeolite-based metal sulfide catalysts have always been dominant in the industrial hydrocracking reaction.The effects of the hydrogenation active phase of zeolite-based metal sulfide hydrocracking catalysts and the acidity and texture properties of their carriers on the catalyst activity and selectivity are summarized and discussed.Further,an analysis is performed on the influence of the balance matching between metal and acid sites(the number ratio of metal sites to acid sites and their distance)on the catalytic performance,and the synergy of the two sites has been discussed in details.Finally,the development of high-efficiency hydrocracking catalysts is reviewed and prospected.