The adsorption and oxidation of SO2 on MgO surface: experimental and DFT calculation studies

CORC > 生态环境研究中心 > 中国科学院生态环境研究中心 > 大气污染控制中心

	The adsorption and oxidation of SO2 on MgO surface: experimental and DFT calculation studies
	Wang, Honghong; Zhong, Cheng; Ma, Qingxin; Ma, Jinzhu; He, Hong
刊名	ENVIRONMENTAL SCIENCE-NANO
	2020-04-01
卷号	7 期号:4 页码:1092-1101
ISSN号	2051-8153
英文摘要	The heterogeneous oxidation of sulfur dioxide (SO2) to sulfate on the surface of MgO particles was investigated by in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and density functional theory (DFT). The in situ DRIFTS spectra show that the major products of SO2 adsorption on MgO particles are sulfite, bisulfite and sulfate, while the coexisting NO2 and O-2 promote the conversion of sulfite/bisulfite into sulfate. DFT calculations show that the main adsorption products of SO2 on the perfect MgO (001) surface, the hydroxylated MgO (001) surface and the step sites of the MgO (001) surface are sulfite (SO2,gas + O-lattice -> SO3,ads), bisulfite and sulfate, respectively. The oxidation of sulfite to sulfate was hardly promoted by the presence of O-2 at room temperature, because the process needs to overcome an energy barrier of 0.67 eV. The existence of NO2 couldn't promote the formation of sulfate, because the direct oxidation of sulfite into sulfate by NO2 is difficult (Delta E-a = 1.08 eV). However, coexisting NO2 with O-2 can facilitate the oxidation of SO2, which illustrates the micro-mechanism of the synergistic effect between SO2 and NO2 on MgO. In contrast to sulfite, surface bisulfite formed through the adsorption of SO2 on surface OH could be oxidized by O-2 or NO(2)via barrierless processes. This mechanism highlights the synergistic effects of O-2/NO2 as well as surface hydroxyl on the heterogeneous oxidation of SO2 on the MgO surface. Atmospheric implications of the heterogeneous oxidation of SO2 on MgO under ambient atmosphere are discussed.
内容类型	期刊论文
源URL	[http://ir.rcees.ac.cn/handle/311016/45104]
专题	生态环境研究中心_大气污染控制中心
推荐引用方式 GB/T 7714	Wang, Honghong,Zhong, Cheng,Ma, Qingxin,et al. The adsorption and oxidation of SO2 on MgO surface: experimental and DFT calculation studies[J]. ENVIRONMENTAL SCIENCE-NANO,2020,7(4):1092-1101.
APA	Wang, Honghong,Zhong, Cheng,Ma, Qingxin,Ma, Jinzhu,&He, Hong.(2020).The adsorption and oxidation of SO2 on MgO surface: experimental and DFT calculation studies.ENVIRONMENTAL SCIENCE-NANO,7(4),1092-1101.
MLA	Wang, Honghong,et al."The adsorption and oxidation of SO2 on MgO surface: experimental and DFT calculation studies".ENVIRONMENTAL SCIENCE-NANO 7.4(2020):1092-1101.