Functionalized graphene sheet as a dispersible fuel additive for catalytic decomposition of methylcyclohexane

Enhanced Fuel Decomposition in the Presence of Colloidal Functionalized Graphene Sheet-Supported Platinum Nanoparticles

“…However, such proton transfer reactions played a major role in previous studies where FGSs were observed to accelerate the flame propagation of liquid nitromethane 23 and the thermal decomposition of methylcyclohexane. 25 The inclusion of Pt@FGS was found to promote both unimolecular and bimolecular reactions (see Figure 8), which is supported by the formation of larger amounts of C 1 −C 4 alkanes and C 2 −C 4 alkenes, compared to the amounts formed by the pyrolysis of pure n-C 12 H 26 . As discussed previously, Pt@ FGS appears to accelerate the overall decomposition during the early stages of reaction via production of a larger radical pool resulting from reactions with lower activation energy (i.e., lower than the barriers associated with C−C and C−H bond scissions or about 335 kJ/mol 62 ).…”

“…37 Before the particles were dispersed, n-C 12 H 26 was sparged with nitrogen at 0.2 MPa for 3 h in order to eliminate the dissolved oxygen in the fuel. 38 Then, 50 ppmw of a Pt@FGS containing 20% by weight Pt was dispersed into n-C 12 H 26 using a tip sonicator, five times for 30 s. From past studies, 14,25,39,40 it was found that the suspension of FGS-based particles remains good for approximately an hour at the very low concentration of 50 ppmw. To minimize any effects related to particle flocculation and sedimentation, all samples were immediately loaded into a pressure syringe pump.…”

“…Additional information on the high-pressure flow reactor and sample separation procedure can be found elsewhere. 25,39 2.3. Analytical Procedures.…”

“…23 Zhang et al 24 have shown the selfenhanced catalytic activities of FGSs in the combustion of NM through chemical adsorptions and atomic interactions using reactive force field molecular dynamic (ReaxFF-MD) simulations. More recently, Sim et al 25 have reported enhanced decomposition of liquid methylcyclohexane with added FGSs. For advanced propulsion applications, the dispersion of nanocatalysts such as nanozeolites 26−28 and metal nanoparticles 29,30 within liquid hydrocarbons has also received considerable attention as a means to improve heat sink capacity and conversion rates under supercritical conditions.…”

“…Previous research ,− has demonstrated that FGSs by themselves act as a catalyst when added to liquid propellants and liquid fuels. Sabourin et al have shown that the combustion of liquid nitromethane (NM, CH 3 NO 2 ) is catalyzed by the inclusion of suspended FGSs, exhibiting increased linear burning rates by up to 175% over neat NM and outperforming the catalytic effects of more conventional additives such as aluminum monohydroxide and silica nanoparticles.…”