Chemical Kinetics Approves the Occurrence of C (³P_j) Reaction with H₂O

Abstract

Although both atomic carbon and water are omnipresent in human life, there is a debate about the possibility of carbon reaction with water. Some low-temperature spectroscopic investigations have rejected the reaction, whereas some room-temperature experiments and theoretical studies have accepted the possibility of the reaction by reporting rate coefficients ranging from 105 to 109 L mol–1 s–1. This study provides new lines of evidence about the reaction through exploration of the reaction mechanism using the CCSD­(T) method and solving the corresponding master equation by following two main approaches. According to the results, the rate coefficient of the reaction is significantly influenced by the tunneling and hindered rotation effects, in addition to the selected total angular momentum (J). Furthermore, the total rate coefficient of the reaction increases dramatically (from 107 to 1011 L mol–1 s–1) with the rise of temperature from 100 to 4000 K, while the total rate coefficient is insensitive to pressure (0.1–10 atm). Despite some differences between the results of the two approaches, the rate coefficients of both methods are consistent with the previously reported rate coefficients. Also, in agreement with the previous studies, the major products are 2HOC + 2H and 2HCO + 2H. In general, the findings approve the occurrence of the title reaction and indicate that the mentioned conflict is due to the sensitivity of the reaction to the investigated temperature and J level. The sensitivity does not permit low-temperature spectroscopic studies to detect any products and varies the measured and calculated rate coefficients.