Catalytic Cracking of JP-10 over HZSM-5 Nanosheets

Catalytic cracking of JP-10 is an important technology to improve its cooling capacity (or heat sink). Two HZSM-5 zeolite nanosheets with Si/Al molar ratios of 25 and 50 (ZNS-25 and ZNS-50) and thicknesses of about 2.0 nm were synthesized. The catalytic cracking of JP-10 (at 500 degrees C with a weight hourly space velocity = 22.56 h(-1)) over ZNS-25 gave a conversion of 45.33%, which is 77% higher than that obtained over a conventional HZSM-5 catalyst (CZ-25, 25.54%), and the deactivation rate was relatively low (two-thirds that of CZ-25). Characterization of the catalysts using ammonia temperature-programmed desorption measurements and Fourier transform infrared spectroscopy indicated that the better catalytic performance may be attributed to more Bronsted acid sites on the external surface, which is favorable for the larger molecules (like JP-10), and higher accessibility of acid sites in the micropores of HZSM-5 nanosheets due to the shorter diffusion path (less than 2.0 nm). The enhanced diffusion of JP-10 over HZSM-5 nanosheets also leads to high olefin yields, and better coking tolerance through prevention of secondary reactions.