Vinyl acetate has a broad range of applications in the market. However, the side reactions of ethylene decomposition and CO formation have a significant effect on the selectivity of vinyl acetate synthesis. In this study, a comprehensive reaction network was calculated by the density functional theory (DFT) method to understand the mechanism of the side reactions. The DFT results indicated that the C-H bond is easier to break than C-C bond except for CCH species during ethylene decomposition on the Pd (100) surface. The introduction of Au on the alloy surface inhibits the decomposition of ethylene, which improves the selectivity of the reaction. The adsorbed O atom inhibits the first three dehydrogenation of ethylene but promotes the CCH species dehydrogenation. The pathway for the decomposition of ethylene is: CHCH → CHCH → CHCH → CCH → C+CH, and the C-C bond cleavage of CCH is identified as the rate-determining step. The rate-determining step for CO formation is the combination of carbon and oxygen atoms to produce CO, and the alloy surface presents a high energy barrier, hindering CO production. This study presents a further mechanistic insight into ethylene decomposition and CO formation, which has implications for the control of side reactions in vinyl acetate synthesis.

中文翻译：

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乙酸乙烯酯合成中 Pd 催化乙烯分解的机理

醋酸乙烯酯在市场上有着广泛的应用。然而，乙烯分解和CO形成的副反应对乙酸乙烯酯合成的选择性有显着影响。本研究通过密度泛函理论（DFT）方法计算了综合反应网络，以了解副反应的机理。 DFT结果表明，在Pd(100)表面乙烯分解过程中，除了CCH以外，CH键比CC键更容易断裂。合金表面引入Au抑制了乙烯的分解，提高了反应的选择性。吸附的O原子抑制乙烯的前三个脱氢，但促进CCH物种脱氢。乙烯分解的路径为：CHCH→CHCH→CHCH→CCH→C+CH，确定CCH的CC键断裂为限速步骤。 CO形成的速率决定步骤是碳和氧原子结合产生CO，合金表面呈现出高能垒，阻碍CO的产生。这项研究对乙烯分解和 CO 形成提供了进一步的机理见解，这对于控制醋酸乙烯酯合成中的副反应具有重要意义。