Preparation of Nano-sized Ceria and Analysis of Its Peroxidase Activity

Abstract

In order to prepare mimetic enzyme with hydrogen peroxide catalytic activity, CeO2 was used as the research object in this paper, and nano-sized CeO2 particles with peroxidase activity were prepared by hydrothermal method. The effect of preparation conditions of hydrothermal synthesis on catalytic performance of nano-sized CeO2 for hydrogen peroxide was studied by the color reaction of Tetramethylbenzidine (TMB), including solid-liquid ratio, reaction temperature and reaction time. A nano-sized CeO2 with the best catalytic activity was selected. Its structure was characterized and its steady-state kinetics of catalytic reaction was studied. The results showed that when the ratio of solid to liquid was 1:60 g/mL, the reaction temperature was 80 ℃ and the reaction time was 8 h, the absorbance value was the largest, which was 0.501, and the catalytic performance of nano-sized CeO2 prepared by hydrothermal method was the best. The nano-sized CeO2 crystals synthesized possessed fluorite structure. The catalytic reaction was in good agreement with the Michaelis-Menten equation, and the Km value for H2O2 was 0.021 mmol/L. The results demonstrated that CeO2 synthesized under simple reaction conditions in excellent purity showed high performance catalysts for H2O2.

Keywords

• mimetic enzyme
• peroxidase
• nano-sized ceria
• catalytic performance
• structure characterization