Catalyst having a zeolitic core and zeolitic layer and the use of the catalyst for olefin oligomerization

摘要

A molecular sieve comprising a core having deposited thereon a surface layer, wherein the core is a zeolite containing silicon and at least one element selected from gallium and iron and the surface layer has a higher Si:Al ratio than that of the silicon:selected element ratio of the core, provides for lower branching in olefin oligomerization products.