No abstract

The effectiveness of the oxidation of carbon dioxide gas emitted by an internal combustion engine was studied.• The CO conversion positively depends on Cu loading, light intensity, and relative humidity.• The best photo-oxidation efficiency of 56.4% was achieved after three hours of operation.Road transportation in urban areas may be considered a major source of environmental pollution. The purpose of this study is to determine the effectiveness of the oxidation of carbon dioxide gas emitted by an internal combustion engine. This is achieved using an asphaltic pavement coated with Cu/TiO 2 nanoparticles by spraying and irradiating with white light under ambient conditions to reduce the air pollution problem (carbon monoxide) caused by vehicles. Using electron microscopy, energy dispersive spectroscopy, and Fourier transform infrared spectroscopy, we determined the physicochemical and morphological characteristics of the photocatalyst. Following the characterization study, the photo-catalytic activity of the asphalt materials was determined.Experimental results showed that CO conversion positively depends on different conditions, including Cu loading, light intensity, and relative humidity. However, the gas flow rate showed a different trend. The optimal operating parameters were determined as follows: Cu loading (3.6% by weight), a flow rate of gas (1 L/min), relative humidity (30%), and light intensity (35 W/m 2 ) to ensure the best photo-oxidation efficiency of 56.4% after three hours of operation. A mathematical correlation related to CO 2 removal as a function of different operating conditions was found with a correlation factor of 0.975 and a variance equal to 0.964. Moreover, a kinetic pathway for photo-oxidation of CO at various oxygen concentrations was presented.