Effects of synthetic parameters on the catalytic performance of Au/CeO2 for furfural oxidative esterification

The synthetic parameters affecting the catalytic performance of Au/CeO2 in furfural oxidative esterification were investigated. Thermal analysis, N-2 adsorption/desorption, X-ray powder diffraction, high-resolution transmission microscopy, CO pulse chemisorption, and diffuse reflectance UV-Vis NIR and transmission FTIR spectroscopies were employed to study the effect of different ceria supports on the nature of the gold species and on catalytic activity. Unexpectedly, the larger the gold size, the higher is the activity, whereas no influence on the selectivity to methyl-2-furoate has been observed. Lower amounts of carbonate species and more coordinated Ce4+ sites at the surface of the most active catalyst calcined at 500 degrees C can explain the enhanced activity. A clean surface is directly related to the capability of ceria to provide activated oxygen. Reverse oxygen spillover can occur at the perimeter of the Au nanopartides, and these gold sites could be involved in the activation of methanol.