Selective and stable benzene alkylation with methane into toluene over PtH-MFI bifunctional catalyst

This paper demonstrates for the first time that methane reacts with benzene over bifunctional PtH-MFI catalyst with selective and stable formation of toluene at such low temperature as 370 C. Our results show that the catalyst activity increases during the initial period of the reaction (4 h) and that this increase is likely associated with the modification of the Pt particles with the surface carbonaceous species (e.g. CH3, CH2, CH, C, and C2Hx). The highest catalyst activity is observed at time on stream (TOS) of 4 h, when toluene selectivity is around 96 mol% and conversions of benzene (4.5%) and methane (0.53%) are close to the equilibrium conversions (5.6% and 0.62% for benzene and methane, respectively). At higher TOS, the catalyst activity declines slowly and at TOS of 23 h conversions of benzene and methane are around 3.8% and 0.45%, respectively. To the best of our knowledge, the reaction of benzene alkylation with methane into toluene, reported in this paper, is the first example of the catalytic reaction involving methane that proceeds continuously during many hours under non-oxidizing conditions.