A theoretical study on the hydrolysis mechanism of carbon disulfide

The hydrolysis mechanism of CS2 was studied using density functional theory. By analyzing the structures of the reactant, transition states, intermediates, and products, it can be concluded that the hydrolysis of CS2 occurs via two mechanisms, one of which is a two-step mechanism (CS2 first reacts with an H2O, leading to the formation of the intermediate COS, then COS reacts with another H2O, resulting in the formation of H2S and CO2). The other is a one-step mechanism, where CS2 reacts with two H2O molecules continuously, leading to the formation of H2S and CO2. By analyzing the thermodynamics and the change in the kinetic function, it can be concluded that the rate-determining step involves H and OH in H2O attacking S and C in CS2, respectively, causing the C=S double bond to change into a single bond. The two mechanisms are competitive. When performing the hydrolysis of CS2 with a catalyst, the optimal temperature is below 252°C.