Study on catalytic decomposition of vehicle exhaust pavement materials by TiO2

Abstract

To achieve low-carbon development and reduce greenhouse gas emissions, it is urgent to solve the problem of automobile exhaust emissions. The photocatalytic material nano titanium dioxide is applied to asphalt pavement to realize the catalytic decomposition of automobile exhaust gas, and achieve the purpose of energy conservation, emission reduction, and environmental protection. In this paper, the photocatalytic efficiency of tail gas degradation of TiO2 thin layer asphalt mixture and TiO2 micro surface asphalt mixture was studied, and the influence of different light intensity on the photocatalytic efficiency of tail gas degradation of the mixture was analyzed. The results show that, with the increase of TiO2 content in the mixture, the tail gas degradation efficiency of the TiO2 thin layer and TiO2 micro surface type mixture increases at first and then becomes stable. In the TiO2 thin layer mixture, when the content of TiO2 reaches 90% (accounting for the mass of ore powder), the cumulative decomposition rates of NO, HC and CO are 43.8%, 19.5%, and 26.1%, respectively, under outdoor natural light. Under ultraviolet light, the cumulative decomposition rates of NO, HC, and CO were 50.6%, 25.12% , and 29.33%, respectively. In the TiO2 microsurface type mixture, when the content of TiO2 reaches 75%(accounting for the mass of ore powder), the cumulative decomposition rates of NO, HC, and CO are 49%, 24.3%, and 26%, respectively, under outdoor natural light. Under ultraviolet light, the cumulative decomposition rates of NO, HC, and CO were 53.9%, 27.6%, and 29.8% respectively. Therefore, compared with outdoor natural light, the asphalt mixture with the same TiO2 content has a higher cumulative decomposition rate of NO, HC, and CO under ULTRAVIOLET light. Under the same experimental conditions, the utilization efficiency of TiO2 microsurface type mixture for TiO2 photocatalyst is better than that of TiO2 thin layer type mixture. Considering the degradation effect of tail gas and the utilization efficiency of TiO2 photocatalyst, the optimal TiO2 content of thin layer mixture is 60% (accounting for the mass of ore powder), and that of micro surface type mixture is 50% (accounting for the mass of ore powder).