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Investigation of Methane Oxidation Reactions Over a Dual‐Bed Catalyst System using 18 O Labelled DRIFTS coupling
Author(s) -
Richard Melissandre,
Duprez Daniel,
Bion Nicolas,
Can Fabien
Publication year - 2017
Publication title -
chemsuschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.412
H-Index - 157
eISSN - 1864-564X
pISSN - 1864-5631
DOI - 10.1002/cssc.201601165
Subject(s) - catalysis , formate , chemistry , oxidative coupling of methane , methane , heterogeneous catalysis , inorganic chemistry , diffuse reflectance infrared fourier transform , oxygen , partial oxidation , singlet oxygen , photochemistry , decomposition , photocatalysis , organic chemistry
Low loading Pd‐supported (0.2 wt % Pd) Y‐stabilized zirconia (YSZ) and LaMnO 3 (LM) perovskite were associated to study the partial oxidation of methane using labelled 18 O 2 in the gas phase. Synthesis gas production was demonstrated to occur through an indirect reaction in which oxygen is first consumed in the total methane combustion. A Mars–van Krevelen mechanism was observed over Pd/YSZ at 425 °C to yield C 16 O 2 and C 16 O. A significant enhancement of the Pd/YSZ catalyst activity was achieved by the association of LM–Pd/YSZ in a dual catalyst bed, resulting in a significant increase of the oxidation rate. Vibration bands of adsorbed formate species, assumed to be intermediates to the gas production, were observed by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) coupling experiments. It was proposed that LM enables the generation of highly active singlet O 2 , which is activated on the YSZ oxygen vacancies to assist a rapid recovery of surface PdO and increase formate decomposition into CO and H 2 in Pd‐supported catalyst.