Low-temperature water-gas shift reaction over ZnO-supported gold nanoparticle catalyst

The effects of preparation methods and conditions on the catalytic performance of the ZnO-supported gold nanoparticle catalyst (Au/ZnO) were investigated for low-temperature water-gas shift (WGS) reaction. It was found that the catalytic performance of Au/ZnO could be considerably influenced by various factors, such as preparation methods, precipitant types, calcination temperature and gold loading. Among the catalyst samples, the 5 % Au/ZnO sample prepared by the co- precipitation method using Na2CO3 as precipitant and calcined at 240 degrees C exhibited the highest activity for the WGS reaction. The results of X-ray diffraction, N-2 adsorption and transmission electron microscopy suggested that the change of preparation parameters could affect the dispersion state of gold species and the size or the specific surface area of the ZnO support, thus considerably influenced the catalytic activity of the Au/ZnO catalyst. Moreover, the existence of a moderate amount of Cl ions in the catalyst might also have a positive effect on the catalytic performance of the catalyst.