The co-processing of acetic acid with methane (CH3COOH/CH 4 = 0.04-0.10) on Mo/ZSM-5 formulations at 950 K and atmospheric pressure in an effort to couple deoxygenation and dehydrogenation reaction sequences results instead in a stratified reactor bed with upstream CH 4 reforming with acetic acid and downstream CH4 pyrolysis. X-ray absorption spectroscopy and chemical transient experiments show that molybdenum carbide is formed inside zeolite micropores during CH4 reactions. The introduction of acetic acid oxidizes a fraction of these carbide moieties upstream while producing H2 and CO mixtures until completely consumed. Forward rates of CH4 pyrolysis are unperturbed in the presence of an acetic acid or hydrogen co-feed after rigorously accounting for the reversibility of pyrolysis rates and the fraction of molybdenum carbide oxidized by CH3COOH implying that all consequences of CH 3COOH and H2 co-feeds can be interpreted in terms of an approach to equilibrium.
Bibliographical noteFunding Information:
Do-Young Hong was supported as part of the Catalysis Center for Energy Innovation, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award No. DE-SC0001004. Jeremy Bedard was supported by the National Science Foundation Emerging Frontiers in Research and Innovation – Hydrocarbons from Biomass (NSF EFRI HyBi # 0937706). The authors also acknowledge financial support from the DOE Early Career Program under Award No. DE-SC0008418. We thank Prof. Jingguang Chen and Dr. Nebojsa Marinkovic for assistance with the X-ray absorption spectroscopy studies. We also thank Nancy Trejo for assistance with catalytic reactions.
- Acetic acid
- Hydrogen transfer
- Kinetic coupling
- Molybdenum carbide