| Popis: |
The hydrolysis of formaldehyde (HCHO) assisted by bimolecular acidic catalysts of H2SO4●●●H2O and (H2SO4)2 under different concentrations of H2SO4 and H2O were performed by quantum chemical calculations and the Master Equation method. The calculated results show that H2SO4●●●H2O and (H2SO4)2 catalyzed hydrolysis reaction of HCHO can occur through both one-step route and stepwise process. Effective rate coefficients (kt′) within the temperature range of 280-320 K show that H2SO4●●●H2O assisted reaction via stepwise route exerts the strongest catalytic role in increasing the rate of the hydrolysis of HCHO among all the hydrolysis reactions with H2SO4●●●H2O and (H2SO4)2 with its effective rate coefficient larger by at least 1 order of magnitude. As compared with the naked hydrolysis of HCHO, the favorable route of the hydrolysis of HCHO with H2SO4●●●H2O can reduce the energy barrier by 32.0 kcal·mol-1. Meanwhile, this reaction is also lower by another 0.8-17.6 kcal·mol-1 than that with H2SO4, HCOOH, HNO3, CH3COOH, H2O and (H2O)2. The calculated kt′ also reveals that the hydrolysis of HCHO with H2SO4●●●H2O ([H2SO4] =108 molecules∙cm-3 and [H2O] at 20%-100% RH) is more effective than that with H2O and (H2O)2 within 280-320 K, and can compete well with the hydrolysis of HCHO in the presence of HCOOH (2-10 ppbv), HNO3 (1011 molecules●cm-3), CH3COOH (1-5 ppbv) within 280-320 K. So, this work predicts that H2SO4●●●H2O can play a significant role in the hydrolysis of HCHO in the condition of wet areas with relatively high H2SO4-polluted. |
