Volcano-Curves for Dehydrogenation of 2-Propanol and Hydrogenation of Nitrobenzene by SiO2-Supported Metal Nanoparticles Catalysts As Described in Terms of a d-Band Model

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• 作者：Masazumi Tamura ; Kenichi Kon ; Atsushi Satsuma ; Ken-ichi Shimizu
• 刊名：ACS Catalysis
• 出版年：2012
• 出版时间：September 7, 2012
• 年：2012
• 卷：2
• 期：9
• 页码：1904-1909
• 全文大小：318K
• 年卷期：v.2,no.9(September 7, 2012)
• ISSN：2155-5435

文摘

To confirm whether the activity trends in multistep organic reactions can be understood in terms of the Hammer鈥揘酶rskov d-band model in combination with the linear energy relations, we studied correlations between the reaction rates for dehydrogenation and hydrogenation reactions and the position of the d-band center (蔚_d) relative to the Fermi energy (E_F), the 蔚_d 鈥?E_F value, of various metal catalysts. SiO₂-supported metal (M = Ag, Cu, Pt, Ir, Pd, Rh, Ru, Ni, and Co) catalysts with the same metal loading (5 wt %) and similar metal particle size (8.9鈥?1.7 nm) were prepared. The dehydrogenation of adsorbed 2-propanol in a flow of He and the hydrogenation of adsorbed nitrobenzene in a flow of H₂ were tested as model reactions of organic reactions on the metal surface. As a test reaction of H₂ dissociation on the surface, SiOH/SiOD exchange on the M/SiO₂ catalysts in a flow of D₂ is carried out. The liquid phase hydrogenation of nitrobenzene under 3.0 MPa of H₂ is adopted as an organic reaction under realistic conditions. Generally, the activities show volcano-type dependences on the 蔚_d 鈥?E_F value, indicating that the 蔚_d 鈥?E_F value is useful as a qualitative activity descriptor in heterogeneous catalysis of metal nanoparticles for multistep organic reactions.

Keywords:

transition metals; trend in catalytic activity; d-band center