Depending on the IO approaches the configuration of HONO, two different H-extraction pathways (IO + cis-HONO and IO + trans-HONO) were located at the CCSD(T)//ωB97X-D level. With the introduction of single water molecule, nine pathways were investigated for the IO + HONO reaction. The computed results manifested that the barriers of Pathway W11, Pathway W12, Pathway W21A, Pathway W21B, Pathway W22B, and Pathway W23 are reduced by 0.39, 3.05, 8.14, 12.63, 13.13, and 10.02 kcal/mol, respectively. The rate coefficients of the reaction of IO + cis-HONO and IO + trans-HONO at 298.15 K in the existence of water are 5.98 × 10⁻¹³ and 4.93 × 10⁻¹¹ cm⁻³ molecule⁻¹ s⁻¹, which are lower than the corresponding reactions in the absence of water (1.14 × 10⁻¹⁴ and 1.39 × 10⁻¹⁹ cm⁻³ molecule⁻¹ s⁻¹). To further comprehend the influence of H₂O on the IO + HONO reaction, the effective rate coefficients were computed through taking account on the water concentration. The effective rate coefficients of the IO + trans-HONO reaction are much larger than the IO + trans-HONO reaction in the absence of water, 'as water molecule could cause the inhibition of the IO + cis-HONO reaction. In contrast to the IO + HONO reaction with water-free, the feasible reaction is the IO + trans-HONO instead of the IO + cis-HONO reaction. The current investigation proved that water possesses positive influence on the IO + trans-HONO reaction, which could devote to the degradation of HONO.

根据 IO 接近 HONO 的配置，两种不同的 H 提取途径（IO +  cis -HONO 和 IO +  trans -HONO）位于 CCSD(T)//ωB97X-D 水平。通过引入单个水分子，研究了 IO + HONO 反应的九种途径。计算结果表明，Pathway W11、Pathway W12、Pathway W21A、Pathway W21B、Pathway W22B 和 Pathway W23 的能垒分别降低了 0.39、3.05、8.14、12.63、13.13 和 10.02 kcal/mol。IO + cis -HONO 和IO +  trans -HONO 在水存在下在298.15 K反应的速率系数为 5.98 × 10 ^-13和4.93 × 10 ^-11  cm ^-3分子^-1  s ^-1，低于不存在水时的相应反应（1.14 × 10 ^-14和1.39 × 10 ^-19  cm ^-3分子^-1  s ^-1）。为了进一步了解H ₂ O 对IO + HONO 反应的影响，通过考虑水浓度来计算有效速率系数。IO + trans -HONO 反应的有效速率系数 远大于 IO +  trans -HONO 反应在没有水的情况下，因为水分子会导致 IO +  cis的抑制-HONO 反应。与无水的 IO + HONO 反应相比，可行的反应是 IO +  trans -HONO 而不是 IO +  cis -HONO 反应。目前的研究证明，水对 IO +  trans -HONO 反应具有积极影响，可用于 HONO 的降解。