Design and preparation of Pt@SSZ-13@β core-shell catalyst for hydrocracking of naphthalene

Abstract

A Pt@SSZ-13@β core-shell catalyst is designed and successfully prepared for investigating the effects of spillover hydrogenation on hydrocracking of naphthalene. The Pt NPs encapsulated in SSZ-13 cages are inaccessible to naphthalene due to its lager size than the pore size of SSZ-13. Thus, hydrogenation functional over Pt@SSZ-13@β is mainly realized via spillover hydrogenation. Pt@SSZ-13@β exhibits higher selectivity to the desired BTX and less naphthenic products than (Pt/SSZ-13)@β and Pt/(SSZ-13@β) at above 90 % naphthalene conversion. These results indicate the hydrogenation modes resulting from the location of the supported Pt NPs in core-structure catalysts can affect the metal-acid balance, and the spillover hydrogenation can effectively suppress the deep hydrogenation of tetralin in hydrocracking of naphthalene, thereby changing the reaction path and improving the selectivity of BTX. In addition, Pt@SSZ-13@β shows a better sulfur-tolerant ability than Pt/(SSZ-13@β). This work provides a new synthetic strategy for preparing zeolite-based bifunctional catalyst.