The effect of Ga, V, and Zr content on the structural properties and the catalytic behavior of H-ZSM-5 monolithic catalysts-supported gallium oxide, vanadium oxide, and zirconium oxide in the oxidative dehydrogenation of propane (ODHP) have been investigated in a continuous tubular microreactor using CO2 as a mild oxidant. The SEM-EDX confirmed the homogeneous distribution of metal oxides within printed metal oxide/H-ZSM-5 monolithic catalysts The ODHP reaction was carried out in the absence of CO2 (5 mol% propane, balanced with N2) and presence of CO2 (2.5 mol% propane, 5 mol% CO2 balanced with N2) at 500, 550, 600, and 650 ℃, 1 bar, and a space velocity of 4500 mL/gcat.hr. Among all synthesized Ga, V, and Zr/H-ZSM-5 monolithic catalysts, 15V-15Zr@ZSM-5 catalyst exhibits both high activity and stability for dehydrogenation of propane, with a propane conversion of 38 % and propylene selectivity of 90 % without any observable trend of benzene, toluene, xylene (BTX) production and catalyst deactivation in 6 h time on stream. The catalyst’s stability is also enhanced by the introduction of CO2. In the absence of CO2, more coke formation was observed which was in addition to the reduced conversion of propane and propylene selectivity by ∼1−5 %.
