以Hβ为内核、十六烷基三甲基溴化铵为模板剂、偏硅酸钠为硅源，采用附晶生长法在Hβ表面包覆了一层MCM-41介孔相。分别以Hβ、MCM-41、包覆型复合分子筛（βM）以及Hβ和MCM-41机械混合物（β+M）作载体，采用等体积浸渍法制备了Pt催化剂。以二苯并噻吩（DBT）为模型含硫化合物，考察了催化剂的加氢脱硫（HDS）反应性能。结果表明，引入酸性Hβ载体不同程度地提高了催化剂的HDS活性，但也加剧了HDS产物的裂化反应。Pt/βM的HDS活性与Pt/Hβ接近，显著高于Pt/MCM-41和Pt/β+M。DBT在Pt/MCM-41上以直接脱硫路径为主，且不发生裂化反应。Pt/βM兼具很高的HDS活性和较低的裂化选择性，同时预加氢路径选择性也有所提高，说明包覆型βM复合分子筛是一种潜在的优异深度HDS催化剂载体。

A layer of MCM-41 mesoporous phase is coated on the surface of Hβ molecular sieves via an overgrowth approach by using Hβ molecular sieve as the core,cetyltrimethylammonium bromide as the template and sodium silicate hydrate as the silicon source.Pt catalysts are prepared through an incipient wetness impregnation method by respectively supporting over Hβ,MCM-41,coated composite (βM),and a mechanical mixture of Hβ and MCM-41 (β+M).Hydrodesulfurization performances of these Pt catalysts are evaluated by using dibenzothiophene (DBT) as the model sulfur-containing molecule.Results indicate that the addition of acidic Hβ support improves the hydrodesulfurization activity of Pt catalysts to a certain extent,but also facilitates cracking reaction of hydrodesulfurization products.The hydrodesulfurization activity of Pt/βM approaches to that of Pt/Hβ,which are both significantly higher than those of Pt/MCM-41 and Pt/β+M.DBT goes mainly the direct desulfurization pathway over Pt/MCM-41,without cracking reaction.However,severe cracking is observed over Pt/Hβ and Pt/β+M,respectively.Pt/βM possesses a high HDS activity and a low cracking selectivity as well as an enhanced selectivity in hydrogenation pathway.All these features make βM a promising support for deep desulfurization catalysts.

杨轶博(1999-),男,本科生,研究方向为加氢脱硫,1376616206@qq.com