posted on 2024-09-30, 21:29authored byDababrata Paul, Souvick Biswas, Hyeonji Yeom, Kyungsu Na, Michelle L. Pantoya, Ralf I. Kaiser
Nanosheet MFI zeolites (Zeolite Socony Mobil, five) have
grown
in popularity in cracking catalysis considering their tunability in
porous topologies, acidic sites, and sheet thickness, thus allowing
them to selectively adsorb molecules of specific sizes, shapes, and
polarities, resulting in improved cracking performance for a specific
fuel. Five different MFI zeolites in the form of a mesoporous nanosheet
structure with a controlled concentration of acidic sites denoted
as NSMFI(y), where y is Si/Al ratio, have been synthesized. The effects
of the relative acidity content of these NSMFI(y) samples on the zeolite-catalyzed
combustion of aluminum nanoparticles (AlNPs)-aided exo-tetrahydrodicyclopentadiene
(JP-10) mixed energetic fuel droplets levitated in an oxygen–argon
atmosphere were investigated using time-resolved imaging (optical
and thermal infrared) and spectroscopic techniques (UV–vis
and FTIR). The addition of 1.0 wt % of NSMFI(y) zeolites to AlNPs-JP-10
fluid fuel results in critically reduced ignition delays (9 ±
2 ms), elevated ignition temperatures (2800 ± 170 K), and prolonged
burning times (60 ± 10 ms) with an enhanced combustion efficiency.
The NSMFI(y) zeolites, which possess high acidity and significant
mesoporosity, play a crucial role in improving the combustion efficiency
by effectively catalyzing the chemical activation of JP-10 and prolonging
the burning of the igniting droplet. The NSMFI (60) variant with the
highest acidic site content achieved a maximum combustion efficiency
of 80 ± 6%. A comprehensive catalytic combustion mechanism has
been elucidated based on the detected reactive intermediates such
as hydroxyl radical (OH) and aluminum monoxide (AlO). These findings
will help to critically advance the development of next-generation,
sustainable, and innovative mixed nanofluid fuels.