Heterogeneous Chemistry of Surface Exchange

表面交换的多相化学

• 批准号: 33855461
• 负责人: Professor Dr. Cornelius Zetzsch
• 金额: --
• 依托单位: Abteilung Atmosphärenchemie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2006
• 资助国家: 德国
• 起止时间: 2005-12-31 至 2010-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/33855461?language=en
• 关键词: Heterogeneous; Chemistry; Surface; Exchange

The heterogeneous processes, catalysed by soluble and insoluble constituents of throughfall, stemflow and soil, leading to an uptake of NO2 and release of HONO, are investigated by employing the wetted-wall flowtube and bubble column methods and a novel photochemical and heterogeneous flowtube to model compounds and to real samples. The dependence of uptake rates on pH can clarify the contributions of aromatic (i.e. phenolic), olefinic, aliphatic and carboxylic structures to the uptake process. The atmospheric relevance can then be demonstrated by selected aerosol chamber experiments at high humidities, enhancing the aerosol surface by coating hydrophilic nanoparticles, made of fused silica, with throughfall and its typical constituents. Realistic NO2 levels are employed and monitored by a Luminol instrument. Formation of nitrous acid (HONO) traces can be detected indirectly by light-induced photochemistry of OH radicals and it will be detected directly by a novel long-path absorption photometer technique (LOPAP). The formation of phytotoxic, nitrated products can be shown by analysis of aerosol samples employing ion chromatography, GC-MS, HPLC-UV and FTIR. In close cooperation with the sub-projects P2 to P4, the rate constants of the relevant heterogeneous reactions are incorporated into the atmospheric chemistry of the trace gas module of the FLAME-SVAT-CN modelling cluster.

采用湿壁流管法和鼓泡塔方法以及一种新颖的光化学和非均相流动管模拟化合物和实际样品，研究了穿透雨、茎流和土壤中可溶和不溶组分催化的非均相过程，导致NO2的吸收和HONO的释放。吸收速率与pH的依赖关系可以阐明芳香族(即酚类)、烯烃、脂肪族和羧基结构对吸收过程的贡献。然后，可以通过选择高湿度下的气雾室实验来证明大气相关性，通过在由熔融二氧化硅制成的亲水性纳米颗粒上涂覆穿透雨及其典型成分来增强气溶胶表面。采用了真实的NO2水平，并由鲁米诺仪器监测。亚硝酸(HONO)的形成可以通过光诱导的OH自由基光化学来间接检测，它将被一种新的长程吸收光度技术(LOPAP)直接检测到。使用离子色谱、GC-MS、HPLC-UV和FTIR对气溶胶样品进行分析，可以显示植物毒性硝化产物的形成。在与子项目P2至P4的密切合作下，相关多相反应的速率常数被纳入FLAME-SVAT-CN模拟集群的微量气体模块的大气化学中。