Premium
Spatial near‐infrared imaging of hydroxyl band coverage on ceria‐based catalysts
Author(s) -
Aiouache Farid,
Oyama Hiro,
Kitagawa Kuniyuki
Publication year - 2006
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.10731
Subject(s) - catalysis , bimetallic strip , absorbance , rhodium , chemistry , methane , dispersion (optics) , infrared , formate , geminal , inorganic chemistry , chemisorption , photochemistry , chemical engineering , organic chemistry , optics , physics , chromatography , engineering
High‐throughput near‐infrared imaging was used to distinguish catalyst activity for low‐temperature methane steam‐reforming. Geminal hydroxyls of reduced ceria were depicted during methane reforming at 673 K. The changes in absorbance maps under various water partial pressures showed evidence of formate intermediate formations without redox exchanges. Higher resolution was observed in absorbance change images than that of thermal images obtained from catalyst surface self‐emissions. The experimental results illustrated higher activity of pure rhodium catalyst than that of bimetallic ones, likely because of the high dispersion of rhodium on the catalyst support. Moreover, the reaction was accelerated when high surface area silica was added because more reduced sites were exposed. Our filter bandwidths limited our interest in band‐shift distribution of geminal hydroxyl band during the reduction process. © 2005 American Institute of Chemical Engineers AIChE J, 2006