Synergistic Effect between SO2and HCOOH on the Surface of CaO

Lingyan Wu, Shengrui Tong, Maofa Ge
2015 Huaxue xuebao  
ACTA CHIMICA SINICA 大气中 SO 2 和 HCOOH 在 CaO 表面的耦合相互作用 吴玲燕 a 佟胜睿 b 葛茂发* ,b ( a 中国气象局大气化学重点开放实验室 中国气象科学研究院 北京 100081) ( b 分子动态与稳态结构国家重点实验室 北京分子科学国家实验室 中国科学院化学研究所 北京 100190) 摘要 矿物气溶胶表面非均相反应由于可以改变气溶胶理化性质以及大气痕量气体平衡而成为大气化学的研究热点. 然而目前关于痕量气体在矿物气溶胶表面的共同吸附研究却很有限. 本研究中采用原位漫反射红外光谱研究了大气中 SO 2 和 HCOOH 在 CaO 表面的耦合相互作用. 通过分析红外光谱以及获取动力学曲线发现 SO 2 和 HCOOH 在 CaO 颗粒 物表面非均相反应相互抑制, 同时通入两种气体时表面产物甲酸盐和亚硫酸盐都减少. 通过分步实验发现 SO 2 和 HCOOH 在 CaO 表面的耦合相互作用主要分为两个方面. SO 2 共同存在时可供吸附的反应活性位点变少从而抑制 HCOOH 在颗粒物表面反应, 导致产物甲酸盐生成量减少. 另一方面对于
more » ... 产物甲酸盐生成量减少. 另一方面对于 SO 2 在 CaO 表面的非均相反应而言, HCOOH 会阻止 SO 2 在颗粒物表面的非均相反应, 使得表面生成亚硫酸盐减少. Abstract Due to altering the properties of particles and the budget of trace gases, heterogeneous reactions on mineral aerosols become an important subject in the atmospheric chemistry. However, synergistic effects between trace gases on the surface of mineral aerosol are largely uncertain. In this work, the synergistic effect between SO 2 and HCOOH on the surface of CaO was studied using in situ Diffusion Reflectance Infrared Fourier Spectroscopy (DRIFTS). From analysing of the spectral features and obtaining the kinetic curves, it is found that the heterogeneous reactions of SO 2 and HCOOH on the surface of CaO blocked each other. In addtion, the formate and sulfite decreased when SO 2 and HCOOH were introduced into the reaction chamber simultaneously. Synergistic effect between SO 2 and HCOOH on the surface of CaO was mainly divided into two aspects according to step-by-step experiments. Less reactive sites available for adsorption because of the coexisting of SO 2 inhibited the reaction of HCOOH on the surface of CaO, resulting in the decrease of the formation of formate. On the other hand, HCOOH could prevent SO 2 from reacting with CaO so that the formation of sulfite decreased.
doi:10.6023/a14120875 fatcat:v3srdehwbnaxzbdqbo7kmhx2pi