Reaction Mechanism of Anthraquinone Hydrogenation over Pd Based Monometallic and Bimetallic Catalyst

作者：Guo, Yanyan; Dong, Yichun^*; Li, Chuanrun^*; Lei, Zhigang^*

来源：Catalysis Letters, 2022, 152(4): 1050-1063.

DOI：10.1007/s10562-021-03692-8

• Pd and Pd-M bimetallic catalyst (M = Ni and Cu)
• Hydrogenation reaction mechanism
• 2-ethylanthraquinone
• Tetrahydro-2-ethyl anthraquinone
• DFT

In this work, the reaction mechanism of 2-ethylanthraquinone (eAQ) and Tetrahydro-2-ethyl anthraquinone (H(4)eAQ) 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 H(4)eAQ over different catalysts is similar. The three benzene rings of eAQ or H(4)eAQ 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-H(4)eAQ 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 H(4)eAQ successively react with the hydrogen atoms on the surface of Pd(111) or PdM to produce anthrahydroquinone (eAQ) and tetrahydroanthrahydroquinone (H(4)eAQ), respectively. Moreover, the simulation results showed that the reaction activation energy for the hydrogenation of H(4)eAQ 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 H(4)eAQ is lower than that of the hydrogenation of eAQ.