Possible atmospheric source of NH 2 SO 3 H: the hydrolysis of HNSO 2 in the presence of neutral, basic, and acidic catalysts.

NH 2 SO 3 H can directly participate in H 2 SO 4 -(CH 3 ) 2 NH-based cluster formation, and thereby substantially enhance the cluster formation rate. Herein, the reaction mechanisms and kinetics for the formation of NH 2 SO 3 H from the hydrolysis of HNSO 2 without and with neutral (H 2 O, (H 2 O) 2 , and (H 2 O) 3 ), basic (NH 3 and CH 3 NH 2 ), and acidic (HCOOH, H 2 SO 4 , H 2 SO 4 ⋯H 2 O, and (H 2 SO 4 ) 2 ) catalysts were studied theoretically at the CCSD(T)-F12/cc-pVDZ-F12//M06-2X/6-311+G(2df,2pd) level. The calculated results showed that neutral, basic, and acidic catalysts decrease the energy barrier by over 18.1 kcal mol -1 ; meanwhile, the product formation of NH 2 SO 3 H was more strongly bonded to neutral, basic, and acidic catalysts than to the reactants HNSO 2 and H 2 O. This reveals that the reported neutral, basic, and acidic catalysts promote the formation of NH 2 SO 3 H from the hydrolysis of HNSO 2 both kinetically and thermodynamically. Kinetic calculations using the master equation showed that (H 2 O) 2 (100% RH) dominate over the other catalysts within the range of 0-10 km altitudes and 230-320 K with its rate ratio larger by at least 2.98 times, whereas HCOOH (3.2 × 10 9 molecules cm -3 ) is the most favorable catalysts at 15 km altitude in the troposphere. Overall, the present results will provide a definitive example that neutral, basic, and acidic catalysts have important influences on atmospheric reactions.