在相对湿度为6%至97%的水-硫酸溶液上H2SO4和CH3SO3H的大量吸附

Mass accommodation of H2SO4 and CH3SO3H on water-sulfuric acid solutions from 6% to 97% RH.

作者信息

Hanson D R

机构信息

Atmospheric Chemistry Division, National Center for Atmospheric Research, Boulder, Colorado 80303, USA.

出版信息

J Phys Chem A. 2005 Aug 11;109(31):6919-27. doi: 10.1021/jp0510443.

DOI:10.1021/jp0510443

PMID:16834049

Abstract

The uptake of H2SO4 and CH3SO3H onto particles composed of water and sulfuric acid was studied in a laminar flow reactor at atmospheric pressure. Their first-order gas-phase loss rate coefficients were determined using a chemical ionization mass spectrometer. Relative humidity was varied from 6% to 97% at 295-297.5 K. The mass accommodation coefficient, alpha, was found to be close to unity for both species. These findings show that alpha does not limit particle growth rates resulting from H2SO4 and CH3SO3H uptake. Diffusion coefficients in N2 for these two species are also reported and a significant dependence upon relative humidity was seen for H2SO4 but not for CH3SO3H. Last, production of small particles was observed due to the presence of SO2 in particle chargers. Formation of these particles can be significantly reduced by adding an OH scavenger such as propane.

摘要

在常压下的层流反应器中研究了硫酸（H₂SO₄）和甲磺酸（CH₃SO₃H）在由水和硫酸组成的颗粒上的摄取情况。使用化学电离质谱仪测定了它们的一级气相损失速率系数。在295 - 297.5 K温度下，相对湿度在6%至97%之间变化。发现这两种物质的质量适应系数α均接近1。这些发现表明，α并不限制因摄取H₂SO₄和CH₃SO₃H而导致的颗粒生长速率。还报告了这两种物质在氮气中的扩散系数，发现H₂SO₄的扩散系数对相对湿度有显著依赖性，而CH₃SO₃H则没有。最后，观察到由于颗粒充电器中存在二氧化硫而产生小颗粒。通过添加丙烷等OH清除剂可显著减少这些颗粒的形成。