(125d) Co-Processing CH4 and CH3COOH 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 acetic acid. The dehydroaromatization of CH4 is known to occur on carburized forms of Mo formed upon elimination of O* from MoOx as COx and H2O upon exposure to CH4. Co-processing acetic acid with CH4 results in a staged reactor configuration where catalytic pyrolysis is suppressed upstream in presence of the oxidant which leads to conversion of MoCx to MoOx structures, which are inactive for pyrolysis reactions of CH4, but which reform active MoCx 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.