Catalytic function of boron to creating interconnected mesoporosity in microporous Y zeolites and its high performance in hydrocarbon cracking

Connectivity of mesopores in zeolites, which is a key factor for the high efficiency catalyst design, is still a challenge to be generated without using organic template. Herein, a hierarchical porous Y zeolite (USYB) was synthesized by introducing catalytic amounts of boron into the framework of NaY, followed by steaming. The introduction of framework boron promoted the hydrolysis of the surrounding Si-O-Al and Si-O-B bonds in steaming treatment. When the boron was dislocated from framework, it could further create more mesopores by steaming. It was deemed that boron played catalytic like role for leading to generate well interconnected mesoporosity. As a result, the mesopore volume of the zeolite increased by 46% relatively. The influence of the generated interconnected mesoporosity on the higher activity was evidenced in both iso-octane (i.e. 2,2,4-trimethylpentane) and 1,3,5-triisopropylbenzene (TIPB) cracking over USYB zeolite. Compared with conventional USY zeolite, there would be 2.1% increase in the yield of gasoline for the cracking of heavy oil over USYB catalyst. (C) 2017 Elsevier Inc. All rights reserved.