Preparation of Au/NiO Catalysts and It′s Catalytic Performance for CO Oxidation

Different preparation methods were used to prepare Au/NiO catalyst and the influence of preparation method on the catalyst activity was investigated.The low temperature oxidation of CO was taken as a probe reaction for comparing the catalyst activity.In order to study the effect of changing support preparation condition on the catalyst activity,a series Au/NiO were prepared by deposition-precipitation method.The XRD,BET and TPR were used to analyze the influence factor on the catalyst activity.The experimental results demonstrated that preparation method influences the catalyst activity.The catalyst prepared by deposition-precipitation showed the highest activity and the catalyst prepared by impregnation method showed the lowest activity.The preparation condition of support also affected the catalyst activity.The addition of dispersant during the support preparation did not obviously improve the catalyst activity.However,the use of microwave in the support preparation was beneficial for increasing the activity of catalyst.The BET results demonstrated that catalysts loaded on uncalcinated supports showed higher activity than those catalysts on calcinated supports.It might be related to the large surface area of the catalysts.The TPR results showed that the catalysts contained oxidation gold and the reduction temperature of oxidation gold correlated well with the catalyst activity.