Rich methane oxidation on Pt/Pd/Al₂O₃: Steady state performance, multiplicity features, and spatial patterns

Journal Article · 07 September 2023 · Chemical Engineering Science

DOI: https://doi.org/10.1016/j.ces.2023.119269 · OSTI ID:2008375

Ratcliff, Jonathan  ^[1]; Karinshak, Kyle ^[2]; Harold, Michael P.  ^[2]

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1. University of Houston, TX (United States); University of Houston
2. University of Houston, TX (United States)

Performance features are reported for the catalytic sub-stoichiometric (rich) oxidation of methane on a Pt + Pd/ Al₂O₃ washcoated monolith over a range of feed temperatures and O₂/CH₄ for both dry and wet feeds. Near isothermal steady state multiplicity and co-existing states with different methane conversions are presented. The methane conversion vs. O₂ feed concentration consists of a higher conversion regime at lower concentrations and a lower conversion, inhibited regime at higher concentration. Here, the conversion maximum is accompanied by an overlap of the two regimes in the form of a clockwise hysteresis loop. Spatial concentration profiles for the dry feed reveal an upstream oxidation zone and downstream stream reforming zone. Measurements extending beyond the catalyst imply the co-existence of active and inhibited states. Addition of water promotes oxidation and steam reforming while the multiplicity and nonuniform states persist. Underlying mechanistic aspects responsible for the inhibition, rate multiplicity and co-existing states are discussed.

• Research Organization: University of Houston, TX (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Energy Efficiency Office. Industrial Efficiency & Decarbonization Office (IEDO)
• Grant/Contract Number: EE0008332
• OSTI ID: 2008375
• Journal Information: Chemical Engineering Science, Journal Name: Chemical Engineering Science Vol. 282; ISSN 0009-2509
• Publisher: ElsevierCopyright Statement
• Country of Publication: United States
• Language: English