(521bt) Selective H2 Combustion over Alkali Metal-Based Catalysts
AIChE Annual Meeting
2023
2023 AIChE Annual Meeting
Catalysis and Reaction Engineering Division
Poster Session: Catalysis and Reaction Engineering (CRE) Division
Wednesday, November 8, 2023 - 3:30pm to 5:00pm
Alkali metal formulations (e.g., Li/MgO and NaWOx) selectively combust hydrogen in mixtures with C1-C3 hydrocarbons in the presence of gas phase oxygen at temperatures ⥠873 K. Heretofore, selective H2 combustion (SHC) has only been reported on redox-active metal oxides; thus, the alkali metal formulations reported herein represent a new class of selective combustion catalysts. H2 combustion selectivities exceeding 80% were observed in H2/CH4/O2, H2/C2H6/O2, and H2/C2H4/O2 mixtures. The use of N2O as an oxidant instead of O2 resulted in higher H2 combustion selectivities over Li/MgO for all binary mixtures studied, suggesting distinct roles of monoatomic and diatomic oxygen species in SHC over irreducible oxides. Probe molecule reaction studies reporting on whether heterolytic or homolytic C-H and H-H reaction pathways enable selection of combustion pathways that otherwise appear unfavorable and spectroscopic studies that probe the identity of oxygen species on the catalyst surface will be discussed.