Adsorption and Reaction of CO2 and SO2 at a Water Surface

• Published in: Journal of the American Chemical Society Vol. 128; no. 10; pp. 3256 - 3267
• Main Authors: Tarbuck, Teresa L, Richmond, Geraldine L
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 15-03-2006
• Subjects: Chemistry; Exact sciences and technology; Gas-liquid interface and liquid-liquid interface; General and physical chemistry; Surface physical chemistry; Inorganic adsorbate; Water; Liquid solid adsorption; Carbon dioxide; Adsorption isotherm; Sum frequency; Inorganic adsorbent; Experimental study; Sulfur dioxide; Infrared spectrometry; Molecular orientation; Liquid vapor interface; Surface properties; Adsorption structure; Surface tension; Interface reaction
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/ja057375a

The orientation and hydrogen bonding of water molecules in the vapor/water interfacial region in the presence of SO2 and CO2 gas are examined using vibrational sum-frequency spectroscopy (VSFS) to gain insight into the adsorption and reactions of these gases in atmospheric aerosols. The results show that an SO2 surface complex forms when the water surface is exposed to an atmosphere of SO2 gas. Reaction of SO2 with interfacial water leads to other spectral changes that are examined by studying the VSF spectra and surface tension isotherms of several salts added to the aqueous phase, specifically NaHSO3, NaHCO3, Na2SO3, Na2CO3, Na2SO4, and NaHSO4. The results are compared with similar studies of CO2 adsorption and reaction at the surface. A weakly bound surface complex is not observed with CO2.