Near-ambient X-ray photoemission spectroscopy and kinetic approach to the mechanism of carbon monoxide oxidation over lanthanum substituted cobaltites

Journal Article · Fri Jul 31 00:00:00 EDT 2009 · Catalysis Communications

DOI:https://doi.org/10.1016/j.catcom.2009.06.022· OSTI ID:974181

Hueso, J L; Martinez-Martinez, D; Cabalerro, Alfonso; Gonzalez-Elipe, Agustin Rodriguez; Mun, Bongjin Simon; Salmeron, Miquel

We have studied the oxidation of carbon monoxide over a lanthanum substituted perovskite (La0.5Sr0.5CoO3-d) catalyst prepared by spray pyrolysis. Under the assumption of a first-order kinetics mechanism for CO, it has been found that the activation energy barrier of the reaction changes from 80 to 40 kJ mol-1 at a threshold temperature of ca. 320 oC. In situ XPS near-ambient pressure ( 0.2 torr) shows that the gas phase oxygen concentration over the sample decreases sharply at ca. 300 oC. These two observations suggest that the oxidation of CO undergoes a change of mechanism at temperatures higher than 300 oC.

• Research Organization: Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: Advanced Light Source Division; Materials Sciences Division
• DOE Contract Number: DE-AC02-05CH11231
• OSTI ID: 974181
• Report Number(s): LBNL-2685E; TRN: US201007%%462
• Journal Information: Catalysis Communications, Journal Name: Catalysis Communications
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ACTIVATION ENERGY
CARBON MONOXIDE
CATALYSTS
KINETICS
LANTHANUM
OXIDATION
OXYGEN
PEROVSKITE
PHOTOEMISSION
PYROLYSIS
SPECTROSCOPY
X-RAY PHOTOELECTRON SPECTROSCOPY
Near-ambient XPS
CO oxidation
Perovskites