Structural and catalytic properties of Au/MgO-type catalysts prepared in aqueous or methanol phase: application in the CO oxidation reaction
Au/MgO and Au/Mg(OH)2-type catalysts for CO oxidation reaction were prepared by using two different synthesis methods in presence of either an aqueous or methanol phase. The influence of the porous and morphological properties of the starting magnesium oxide supports was analyzed and correlated with the catalytic performances of the final gold-supported catalysts. It was found that the deposition of gold in the presence of methanol as a solvent avoids the total rehydration of the MgO support and maintains the textural and morphological properties of the starting oxides. The support synthesized by a surfactant-assisted hydrothermal route, having a combined meso-macroporous structure (i.e., MgO-P) showed a positive influence on the CO oxidation reaction as it favored the dispersion of gold and the surface-to-gas phase interaction during the catalytic process.
This work was partially funded by the IWT—Belgium. The authors would like to thank Sander Clerick and Jonas Billet for their valuable help with the SEM images. A special thank goes to Dr. Anastasios Kambolis (PSI-Switzerland) for the XAS measurements at the Swiss-Norwegian Beam Line (SNBL)—ESRF.
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