CH_4和CO_2合成乙酸中CO_2与·H及·CH_3相互作用的理论计算

Theoretical Calculation for Interaction of CO_2 with ·H and ·CH_3 in Synthesis of Acetic Acid from CH_4 and CO_2

采用量子化学密度泛函方法,对CO2与H及CH3自由基反应进行了理论计算,给出了CO2与H及CH3自由基相互作用的反应机理,提出了CO2与H及CH3自由基作用的4条反应路径.其中以H和CH3自由基进攻CO2的C原子反应为优先路径,主要产物为乙酸,而甲酸甲酯为动力学禁阻产物.计算结果与实验结果相当吻合.为CH4和CO2两步反应合成含氧化合物提供了理论解释和指导.

The reactions of CO2 with H and CH3 radicals were systematically investigated using the quantum chemistry density functional theory. The reaction mechanism of CO2 with H and CH3 radicals was obtained. The pathway that H or CH3 radical attacked the C atom of CO2 was the preferential pathway in all the four designed reaction pathways. The main product was acetic acid, while methyl {ormate was inhibited by dynamics. The calculated result was in accordance with the experimental result, which provided a new illustration and guidance for the direct synthesis of oxygenated compounds from CH4 and CO2 by a two-step reaction method.