Catalytic hydrocracking reactions of tetralin biomass tar model compound to benzene, toluene and xylenes (BTX) over metal-modified ZSM-5 in ambient pressure reactor

The tetralin hydrocracking process into benzene, toluene, and xylenes (BTX) was investigated over metal-modified (Ga, Nb, Ni, NiMo, Sn, W, Zr or H3[P(W3O10)4])/ZSM-5 zeolite catalysts without sulfidation procedures, mechanism analyzed, compared with a pristine microporous material in packed bed reactor under applied atmospheric pressure (p). This experimental study presents an investigation of the metal-promoted ZSM-5 for BTX production ambient p first continuously-operated time. It is demonstrated that metal-wise there are no significant improvements formation BTX. yield 43.1 mol% towards parent HZSM-5 (SiO2/Al2O3 = 30) at 420 °C after 4 h on time stream (TOS) achieved, while methane, ethylene, ethane, propylene propane were main gas products. outstanding functional performance mainly ascribed to structure, its high dealkylation measured large amount solid surface area tandem porosity, protonating total Brønsted (BAS)/Lewis (LAS) acidity BAS/LAS ratio. However, dropped drastically increasing TOS due coke. found most affected within studied reaction conditions, but could be easily regenerated preserving realistic catalytic chemistry. pathway cracking proposed. Simultaneously, 5wt%Zr/ZSM-5 catalyst possessed highest selectivity (SBTX 24.2 mol%; 25 h; 370 °C) low diffusion thermomigration species framework same conditions long TOS. Influence metal loading activity systematically complex relationship between physicochemical properties bifunctional observed. All these findings shed light, how incorporation different metals affects selectivity.