Tuning the acidity and pore structures of NiP based bifunctional catalyst for efficient n-hexane isomerization

Abstract

Isomerization of alkane is one of the most important catalytic processes for producing environmentally friendly gasoline fraction with high octane number. However, the development of non-noble metal based catalysts with high conversion and selectivity towards multi-branched isomerized products is still challenging. Herein, we report that a NiP-Hβ/modified Kaolin catalyst was successfully prepared by ball-milling of amorphous NiP nanoparticles with Hβ/modified Kaolin composites and applied for n-hexane isomerization. The introduction of chemically modified Kaolin with abundant weak-medium acid sites and mesopores not only alleviates the cracking of isomerized products on the strong acid sites on Hβ, but also provides more active sites for the formation of di-branched isomerized products with high octane number. As a result, the NiP-Hβ/modified Kaolin catalyst shows an excellent catalytic performance for n-hexane isomerization in terms of good conversion (78.1%), high selectivity towards mono-branched (75.4%) and di-branched (21.4%) i-C6 products, and high liquid yield (99.9%). This work paves the way to the development of high performance non-noble metal based catalysts for large scale production of clean gasoline.