A Novel B-Doped NiP/Hβ Catalyst for n-hexane Isomerization with Synergistic Catalytic Mechanism of Metal Sites–Acid Sites

Novel B-doped NiP/Hβ (Hβ is the hydrogen proton exchanged β molecular sieve) catalysts were prepared and the catalytic performance for n-C 6 (n-hexane) isomerization was studied firstly. It was found that the mole ratio of Ni, P and B in preparing B-doped NiP had important influence on the crystalline structure and catalytic activity of NiPB. When the mole ratio of Ni, P and B was 1:1:1, the prepared NiPB was amorphous and NiPB/Hβ had the best catalytic activity with the conversion rate of n-C 6 , the yield and selectivity of isoparaffins being 79.93%, 78.34% and 98.01% respectively. It was also showed that the preparation conditions of catalyst including NiPB loading on carrier and calcination temperatures were the key factors for the catalytic performance of NiPB/Hβ. In controlled experiments, ammonia poisoned acid sites on the catalyst led to the markedly reducing of catalytic performance and metal sites were essentially for the dehydrogenation-hydrogenation reaction. The isomerization of n-C 6 catalyzed by NiPB/Hβ is a continuous alternating process of acid catalysis and metal catalysis, and the matching of acid sites and metal sites is of importance. Graphic Abstract