Unimolecular decomposition mechanism of vinyl alcohol by computational study

Although vinyl alcohol(CH₂=CHOH)molecule was found to be an important intermediate in the combustion flames of hydrocarbon (Taatjes et al. in Science 308:1887, 2005), the removal mechanism of vinyl alcohol has not been established yet. The removal mechanism is critical to characterize the kinetics behavior of hydrocarbon in combustion chemistry and to develop the chemical models of hydrocarbon oxidation. In this work, the potential energy surface for the unimolecular decomposition of syn-CH₂=CHOH reaction has been first studied by ab initio. The kinetics and product branching ratios for the decomposition reaction are evaluated by Variflex code in the temperature range of 500–3,000 K at 0.1, 1.0, and 100.0 atmosphere pressure. The results show that the formation of CH₃ + CHO via the CH₃CHO intermediate is dominant in the decomposition reaction and its branching ratios at 0.1, 1.0, and 100.0 atm are more than 99.90, 99.30, and 89.20%, respectively, through the whole temperature range investigated.