(180f) Co-Processing CH4 With Oxygenates On Mo/ZSM-5: Coupling Dehydrogenation and Deoxygenation Pathways

The non-oxidative dehydroaromatization of CH₄ on Mo/ZSM-5 surfaces to near equilibrium conversions involves kinetically-relevant hydrogen removal steps; we seek to exploit the resulting high hydrogen chemical potential for deoxygenation reactions of C₁-C₃ oxygenates. The dehydroaromatization of CH₄ is known to occur on carburized forms of Mo formed upon elimination of O* from MoO_x as CO_x and H₂O upon exposure to CH₄. Co-processing acetic acid, formic acid, and CO₂ with CH₄ results in a stratified reactor configuration where catalytic pyrolysis is suppressed upstream in presence of the oxidant which leads to conversion of MoC_x to MoO_x structures, which are inactive for pyrolysis reactions of CH₄, but which reform active MoC_x after an induction period when exposed to pure CH₄ reactants at reaction conditions. Downstream CH₄ pyrolysis rates can be interpreted in terms of an approach to equilibrium based on the hydrogen formed in the upstream oxidation zone to rigorously show that forward rates for CH₄ dehydroaromatization are unchanged in presence of the oxidant. The potential for coupling CH₄ dehydrogenation with biomass deoxygenation reaction pathways will be discussed in context of these results.