Influence of Preparation Methods on the Performance of Metal Phosphate-Supported Gold Catalysts in CO Oxidation

Abstract

The influence of different preparation methods on the performance of metal phosphate-supported gold catalysts in CO oxidation was surveyed. A series of metal phosphate-supported gold catalysts (Au/M–P–O, M = Al, Ca, Fe, Zn, La, Eu, Ho) were prepared by depositing dodecanethiol-capped gold nanoparticles on the supports, or by using Au(en)2Cl3 as the precursor, and these catalysts were tested in CO oxidation. The catalytic data were compared with the data obtained in our previous work employing catalysts prepared by deposition–precipitation (Ma et al. Catal Lett 126:20). It was found that only Au/La–P–O is always active whereas Au/Al–P–O, Au/Ca–P–O, and Au/Zn–P–O are always not particularly active, regardless of the preparation methods. These catalysts were characterized by TEM, and it was found that the size of gold nanoparticles is not the only factor that determines the activity. Both catalyst supports and preparation methods are important factors. Here we loaded gold on metal phosphates using either dodecanethiol-capped gold nanoparticles or Au(en)2Cl3 as the precursor, tested the activity in CO oxidation, and compared the catalytic results with those obtained using gold-on-phosphate catalysts prepared via deposition–precipitation.