Deactivation and regeneration of Pt‐modified zeolite Beta–Bindzil extrudates in n‐hexane hydroisomerization.

BACKGROUND: The metal–acid bifunctional catalysts are widely used in many industrially significant chemical processes, including hydroisomerization of n‐hexane. Deactivation and regeneration of metal–acid bifunctional extrudates was investigated in continuous n‐hexane hydroisomerization in a fixed‐bed reactor. Four Pt/H‐Beta‐25 catalysts containing 30% Bindzil binder were prepared with the same composition and controlled metal deposition. RESULTS: Different preparation steps led to differences in the mechanical strength, Pt particle size, acidity and strength, metal‐to‐acid site (cPt/cAS) ratio and proximity between two types of active sites. A very slow deactivation and high selectivity to C6 isomers was obtained when Pt was deposited on H‐Beta‐25 zeolite. CONCLUSION: Initial selectivity to the desired products was correlated with the physicochemical properties of the catalysts. Location of the metal has a larger influence on catalyst deactivation of the bifunctional catalysts rather than the metal‐to‐acid site ratio or site proximity. Decline of n‐hexane conversion and selectivity to C6 isomers were correlated with changes in the textural properties and acidity of the deactivated catalyst, respectively. © 2021 The Authors. Journal of Chemical Technology & Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]