Key Laboratory of Atmospheric Composition and Optical Radiation, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences , Hefei 230031, China.
J Phys Chem A. 2013 Jun 20;117(24):5106-16. doi: 10.1021/jp312844z. Epub 2013 Jun 5.
The gas-phase reactions of sulfuric acid catalyzed hydrolysis of formaldehyde and formaldehyde with sulfuric acid and H2SO4···H2O complex are investigated employing the high-level quantum chemical calculations with M06-2X and CCSD(T) theoretical methods and the conventional transition state theory (CTST) with Eckart tunneling correction. The calculated results show that the energy barrier of hydrolysis of formaldehyde in gas phase is lowered to 6.09 kcal/mol from 38.04 kcal/mol, when the sulfuric acid is acted as a catalyst at the CCSD(T)/aug-cc-pv(T+d)z//M06-2X/6-311++G(3df,3pd) level of theory. Furthermore, the rate constant of the sulfuric acid catalyzed hydrolysis of formaldehyde combined with the concentrations of the species in the atmosphere demonstrates that the gas-phase hydrolysis of formaldehyde of sulfuric acid catalyst is feasible and could be of great importance for the sink of formaldehyde, which is in previously forbidden hydrolysis reaction. However, it is shown that the gas-phase reactions of formaldehyde with sulfuric acid and H2SO4···H2O complex lead to the formation of H2C(OH)OSO3H, which is of minor importance in the atmosphere.
采用 M06-2X 和 CCSD(T) 理论方法的高精度量子化学计算以及带有 Eckart 隧道修正的传统过渡态理论（CTST），研究了硫酸催化甲醛和甲醛与硫酸和 H2SO4···H2O 配合物的水解气相反应。计算结果表明，当硫酸在 CCSD(T)/aug-cc-pv(T+d)z//M06-2X/6-311++G(3df,3pd)理论水平下作为催化剂时，甲醛在气相中的水解能垒从 38.04 kcal/mol 降低到 6.09 kcal/mol。此外，与大气中物种浓度相结合的硫酸催化甲醛水解的速率常数表明，硫酸催化剂促进的甲醛气相水解是可行的，对于甲醛的消除（先前被禁止的水解反应）可能非常重要。然而，研究表明甲醛与硫酸和 H2SO4···H2O 配合物的气相反应导致 H2C(OH)OSO3H 的形成，这在大气中意义不大。
