Engineering the Framework Cobalt and Hierarchical Pores of Aluminophosphates for Enhanced Performance in n-Butene Skeletal Isomerization

An effective method is proposed to synthesize a hierarchical Co-doped AlPO4 molecular sieve (CoAIP-CTAB). For the obtained zeolite, both framework and extra framework Co are firstly established and identified by X-ray absorption fine structure (XAFS). The percentage of framework Co (P-O-Co-O-P) is estimated to be 82%. Due to the hierarchical structure and abundant Co sites in the framework, CoAIP-CTAB nanocrystals have shown high catalytic activity and stability for the catalytic conversion of n-butenes to isobutene at mild temperature (350 degrees C) without gas dilution. This novel synthesis strategy may inspire the design of similar types of industrial zeolite catalysts for selective reactions.

Automated summary

An effective method is proposed for synthesizing a hierarchical Co-doped AlPO4 molecular sieve, CoAIP-CTAB, with both framework and extra framework Co identified by XAFS. The obtained nanocrystals show high catalytic activity and stability in the conversion of n-butenes to isobutene, without the need for gas dilution, due to their hierarchical structure and abundant Co sites in the framework. This novel synthesis strategy may inspire the design of similar zeolite catalysts for selective reactions in the industry.