RUI: Far Ultra-Violet (172 nm) Photolysis of Gaseous Anthropogenic Pollutants

该奖项由化学系环境化学科学项目颁发。加州州立大学北岭分校的Mads P.Sulbaek Andersen教授和他的团队研究空气污染物的远紫外线(FUV)光解。挥发性有机污染物是家庭和工业过程中排放的污染物，在地方和全球范围内影响人类和环境健康。该项目研究气相高级氧化工艺(AOPS)背后的化学原理，它可以帮助净化工厂排放点的空气或建造空调系统。AOP的承诺是，该技术可以限制与传统基于过滤器的空气净化系统相关的高能耗。然而，AOPS中使用的FUV光解和过程可能会产生比母体污染物更具毒性的化合物。准确了解与FUV降解有机污染物有关的基本动力学和化学反应途径，对于确定所产生化合物的性质及其环境命运和影响至关重要。这项研究的结果在分子水平上影响了我们对影响城市空气质量的光化学过程的理解。该项目为本科生提供培训机会，并支持一个以本科生为主、为少数族裔服务的机构的研究丰富的学习环境。对于挥发性有机化合物，在FUV波长(~121-200 nm)引发的光解、量子产率和化学氧化机理还不是很清楚。该项目使用了一种温度控制的先进光化学模拟室，配有现场准分子辐射灯和多通道分析光学元件。使用包括傅里叶变换红外光谱和高分辨率真空紫外光谱在内的光学技术来监测反应物和氧化产物。从120-200 nm测量紫外吸收截面，作为温度的函数，工业过程中排放的重要的高容量化合物(芳烃、羰基、含氮化合物)。测量了光解的172 nm量子产率，并研究了光解机理与压力、温度和氧分压的关系。这项研究提供了关于基础光化学的新知识，并用于定量评估有机气体污染物在FUV光化学过程中形成的产物的命运和影响。研究团队主要由这个少数群体服务机构的本科生研究人员组成。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This award is from the Environmental Chemical Sciences Program in the Division of Chemistry. Professor Mads P. Sulbaek Andersen of California State University, Northridge and his group investigate Far Ultra-Violet (FUV) photolysis of airborne pollutants. Volatile organic pollutants are emitted from domestic and industrial processes and impact the human and environmental health on local to global scales. This project investigates the chemistry behind gas-phase Advanced Oxidation Processes (AOPs), which can assist in purification of air directly in factory emission points or in building air-conditioning systems. The promise of AOP is that the technology can limit the high energy consumption associated with traditional filter-based air-cleaning systems. However, the FUV photolysis and processes utilized in AOPs may result in compounds more toxic than the parent pollutant. An accurate understanding of the fundamental kinetics and chemical reaction pathways associated with FUV degradation of the organic pollutants is crucial to determining the nature of the resulting compounds and their environmental fate and impact. The results of this research impact our understanding at a molecular level of photochemical processes that impact urban air quality. The project provides training opportunities for undergraduate students and supports a research-rich learning environment at a primarily undergraduate, minority-serving, institution. Photolysis quantum yields and chemical oxidation mechanisms initiated at FUV wavelengths (~121-200 nm) are not well known for volatile organic compounds. This project uses a temperature-controlled advanced photochemical simulation chamber with in-situ excimer-radiation lamps and multi-pass analytical optics. Reactants and oxidation products are monitored using optical techniques including Fourier transform infra-red spectroscopy and high-resolution vacuum UV spectrophotometry. UV absorption cross sections are measured from 120-200 nm, as a function of temperature, for important, high-volume compounds emitted from industrial processes (aromatics, carbonyls, N-containing compounds). The 172-nm quantum yields of photolysis are measured and the photolysis mechanisms are investigated as a function of pressure, temperature and O2 partial pressure. This research provides new knowledge on fundamental photochemistry and is used for quantitative assessment of the fates and impact of the products formed during FUV photochemistry of organic gaseous pollutants. The research team is largely comprised of undergraduate researchers at this minority serving institution.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.