分子筛和γ-AI 203混合载体上负载Ni和W的加氢裂解催化剂的EXAFS研究

摘要

Four hydrocracking catalysts supported on different kinds of modified Y zeolites were studied by utilizing EXAFS(Extend X-ray Absorption Fine Structure). The results show that the Ni and W in the catalysts have not been thoroughly sulfided. Apart from the sulfided state, the tungsten in the sulfided catalysts exists in a state of oxosulfided tungsten while some nickels exist in their oxide state. In addition,it also shows that there are NiWS species in the sulfided catalysts and the amount of which shows a good correlation with the Bronsted acid sites of the mixture supports of zeolites and γ-Al2Os. It means that the NiWS species maybe exist mainly in the cavities of the zeolites and the tungsten in micropore zeolites is more difficult to be sulfided than that on the surface of amorphous Al2O3.%运用ExAFs技术对Ni负载于4种改性Y分子筛与A12O3混合载体上的加氢裂解催化剂进行了研究，结果表明，硫化态催化剂中W和Ni均未被完全硫化，除硫化态外，大部分W处于钨氧硫(WOs)状态，而部分Ni为氧化物，不同分子筛对Ni和W的硫化程度的影响不同.另外催化剂中存在少量的NiWs相，载体的B酸位与催化剂中的NiWs相的多少有较好的相关性.