Abstract

In this work, the reaction mechanism of 2-ethylanthraquinone (eAQ) and Tetrahydro-2-ethyl anthraquinone (H₄eAQ) hydrogenation over Pd and Pd-M bimetallic catalysts (M = Ni and Cu) was first investigated by density functional theory (DFT) using VASP software. The simulation results showed that the reaction mechanism of eAQ and H₄eAQ over different catalysts is similar. The three benzene rings of eAQ or H₄eAQ are on bridge sites over the surface of Pd(111) or PdM(111). Dihydrogen is preferentially adsorbed on the top site of a Pd atom in Pd-eAQ or Pd-H₄eAQ model, and then the hydrogen atoms dissociated from dihydrogen are located at two neighboring threefold hollow fcc positions. The two carbonyl oxygen atoms of eAQ and H₄eAQ successively react with the hydrogen atoms on the surface of Pd(111) or PdM to produce anthrahydroquinone (eAQ) and tetrahydroanthrahydroquinone (H₄eAQ), respectively. Moreover, the simulation results showed that the reaction activation energy for the hydrogenation of H₄eAQ and eAQ over Pd-Ni bimetallic catalyst is lower than those over other catalysts, which is attributed to the better synergy of Pd and Ni on the surface of Pd-Ni bimetallic catalyst. The reaction activation energy of the hydrogenation of H₄eAQ is lower than that of the hydrogenation of eAQ.

Graphic Abstract

中文翻译：

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钯基单金属和双金属催化剂上蒽醌加氢的反应机理

摘要

在这项工作中，首先通过密度泛函理论研究了2-乙基蒽醌 (eAQ) 和四氢-2-乙基蒽醌 (H ₄ eAQ) 在 Pd 和 Pd-M 双金属催化剂（M = Ni 和 Cu）上加氢的反应机理。DFT) 使用 VASP 软件。模拟结果表明eAQ和H ₄ eAQ在不同催化剂上的反应机理相似。eAQ 或 H ₄ eAQ的三个苯环位于 Pd(111) 或 PdM(111) 表面的桥位上。在 Pd-eAQ 或 Pd-H ₄ eAQ 模型中，二氢优先吸附在 Pd 原子的顶部位置，然后从二氢解离的氢原子位于两个相邻的三重空心 fcc 位置。eAQ 和 H ₄的两个羰基氧原子eAQ 依次与 Pd(111) 或 PdM 表面的氢原子反应，分别生成蒽氢醌 (eAQ) 和四氢蒽氢醌 (H ₄ eAQ)。此外，模拟结果表明，Pd-Ni双金属催化剂上H ₄ eAQ和eAQ加氢的反应活化能低于其他催化剂，这归因于Pd表面Pd和Ni更好的协同作用。 -Ni双金属催化剂。H ₄ eAQ加氢反应活化能低于eAQ加氢反应活化能。

图形摘要