Catalytic combustion of toluene over copper oxide deposited on two types of yttria-stabilized zirconia

Abstract

Yttria-stabilized zirconia (YSZ) was obtained by the coprecipitation at pH 9.0 and by the sol–gel method. These oxide systems crystallized in the tetragonal phase which was revealed by powder X-ray diffraction (XRD). The YSZ supports were mesoporous solids with different kinds of porosity and various BET specific surface areas determined by low-temperature sorption of nitrogen. The incipient wetness technique was used to modify these materials with different amounts of Cu (2.5, 5.0 and 7.5wt%). The changes in structural and textural properties of the YSZ supports after the CuO introduction were discussed, and the surface composition of the Cu-loaded samples was studied by X-ray photoelectron spectroscopy (XPS). It was found that the intra- and interparticle porosity influences the dispersion of CuO active phase, which is the parameter determining the catalytic activity in the toluene combustion. The material based on coprecipitated YSZ containing 5wt% of Cu turned out to be the most active catalyst with T50=264°C and the total conversion of toluene observed at 350°C.