Research On Catalytic Oxidation Of Isopropanol At Normal Temperature

Volatile Organic Compounds（VOCs）are seriously harmful to the atmosphere and human body,which has attracted the attention of relevant state departments in recent years.Alcohols are an important and hazardous component of VOCs.This study explores the normal temperature catalytic oxidation VOCs technology,compared with the traditional VOCs treatment technology,which has the advantages of low investment cost,low operating cost,and high safety factor.We focus on the preparation of new catalysts to achieve catalytic degradation of alcoholic VOCs at normal temperatures.Taking the isopropanol as the research object,noble metal catalyst doped with the alkali metalwas prepared by the impregnation method,and the ozone-assisting catalytic degradation of isopropanol was carried out under normal temperature conditions.The conditions including p H,loading and calcination temperature during catalyst preparation were optimized.The results showed that 1wt%Pt/2wt%Na-TiO₂ catalyst prepared by the impregnation method had the best degradation effect on isopropanol at a calcination temperature of 400℃ and a preparation p H of 8.The Pt/Na-TiO₂ catalysts with different Pt/Na atomic ratios were characterized by SEM.The results showed that the catalysts showed a uniform spherical morphology,and there was no significant change with the change of Pt/Na atomic ratio.BET test showed that the doping of alkali metal had no significant effect on the specific surface area,pore diameter and pore volume of the catalyst.The XRD characterization of the catalyst with different calcination temperatures showed that the Pt and Na particles were small and uniformly dispersed.The Ti2pXPS spectrum showed that the catalyst produced electron transfer between Na and TiO₂ after doping alkali metal.The O1sXPS spectrum of the catalyst showed that the doping of alkali metal can effectively increase the relative content of hydroxyl oxygen.The Pt4fXPS spectrum of the catalyst showed that the valence of Pt increased with the increase of calcination temperature,and the content of Pt（Ⅱ）had a great influence on the catalytic oxidation of isopropanol.In this study,the influence of process conditions including reaction temperature,space velocity,initial concentration of isopropanol,and humidity on the removal of isopropanol was investigated.The effects of catalyst on ozonation of isopropanol at normal temperature indicated that the optimum reaction temperature for the catalytic ozonation of isopropanol was 35℃,the optimum space velocity was 16920h^-1,the optimal initial concentration of isopropanol was 200mg/m³,higher humidity was beneficial to promote the degradation of isopropanol.The catalyst of reactivation was still able to maintain about 90% conversion of isopropanol at the end of the fourth cycle.In addition,the power law model was used to analyze the reaction process of normal temperature catalytic ozonation of isopropanol,and the apparent activation energy of the reaction was Ea=29.74kJ/mol.