Research On Catalytic Reduction And Modeling Of Near-earth Atmosphere Ozone Based On Catalytic Functional Coatings On Building Exterior Walls

After 30 years of effort to treat air pollution in China,there has been a noticeable improvement in air quality,with the concentrations of particulate matter,SO₂,NO₂and CO in Beijing meeting national secondary standards.In recent years,there is a rise in ozone pollution.Due to the nonlinear relationship between ozone and its precursors,the traditional method of treating ozone pollution involves reducing collaborative emissions of NOx and VOCs.However,this approach can be expensive.To address the challenges associated with conventional ozone pollution control measures,this study conducted research on catalytic reduction and modeling of near-earth atmospheric ozone using catalytic coatings for building exterior walls.This study focuses on analyzing the characteristics of ozone pollution in Huangcun,Daxing District,Beijing,and determining the peak reduction volume of ozone pollution in the area.The study then conducted outer tunnel and outer wall tests by coating the exterior wall with a catalytic coating to observe and simulate the ozone reduction effect.The goal of this research is to explore a new approach to controlling ozone pollution.The results showed that:（1）Huangcun,located in Daxing District of Beijing,experiences seasonal variations in high levels of ozone pollution.Meteorological factors play a significant role in the occurrence of ozone pollution.Analysis of ozone pollution data from recent years indicates that the average daily ozone concentration in Huangcun during the pollution period needs to be reduced by approximately 35.8μg/m³to meet the national secondary standards.（2）The study found that the catalytic coating has a significant effect in reducing ozone,as evidenced by both the field tunnel and building exterior wall tests.The effect of the catalytic coating on ozone reduction decreases in a stepwise manner as the distance from the coating surface increases.In the application test on building exterior walls,the closest monitoring point（4 m）to the catalytic coating wall showed the best ozone reduction effect,with a reduction of 9 ppb.The daily average concentration of ozone in the entire application area decreased by 7 ppb,resulting in an overall reduction rate of 11.7%.（3）The ozone reduction effect of the catalytic coating was analyzed through a field test and subsequent simulation.The results indicate that the catalytic coating has a clear ozone reduction boundary,and the effectiveness of the coating decreases exponentially as the distance from its surface increases within this boundary.The ozone reduction boundary of catalytic coatings varies in different simulation experiments.In tunnel simulations,the ozone reduction boundary is approximately 15 cm,while in building exterior wall simulations,it is about 8.5 m.Additionally,it was observed that wind speed does not significantly affect the catalytic reduction boundary of the paint,but it does decrease the ozone reduction effect.Furthermore,there is a positive correlation between the ozone reduction effect of catalytic coatings and the coating area.According to the building simulation results,it has been calculated that only 34.03%of the total building area needs to be coated with catalytic coatings to effectively reduce ozone in a 1 km²area.By doing so,the ozone concentration in the area can meet the standard requirements.In the Huangcun area of Daxing District,catalytic coatings are being used to reduce ozone levels in order to meet the national secondary standard.The application of these coatings covers an area of approximately 1.3-1.8 million m²in Huangcun.In the Huangcun area of Daxing District,catalytic coatings have been utilized to reduce ozone concentration to meet the national secondary standard.The application of catalytic coatings in this area spans over 1.3-1.8 million m².The economic cost and health benefits of the coatings have been calculated,and it has been found that the use of catalytic coatings can save 24,000 to40 million yuan in comparison to the cost of emission reduction.Additionally,the health benefits of the coatings can reduce 397 deaths in Huangcun,Daxing District.If catalytic coatings are applied in Beijing to control ozone concentration below the national secondary standard,an area of about 290-390 million m²would need to be coated.The economic cost of such an application can save 4.2-7.3 billion yuan in comparison to the cost of emission reduction.Furthermore,this program can reduce175,105 deaths in Beijing.The use of catalytic functional coatings to reduce ozone concentration has proven to be highly efficient and has significant economic and health benefits.It is a feasible solution to regional ozone pollution.