US EPA

4270433 

Journal Article 

The Nature of Synergetic Effect of Manganese Oxide and Platinum in Pt-MnOX-Alumina Oxidation Catalysts 

Yashnik, SA; Ishchenko, AV; Dovlitova, LS; Ismagilov, ZR 

2017 

1 

Topics in Catalysis
ISSN: 1022-5528
EISSN: 1572-9028 

60 

1-2 

52-72 

10.1007/s11244-016-0722-8 

WOS:000395015100006 

The phase and chemical compositions, size and morphology of Pt particles, manganese oxides, and alumina in the binary Pt-MnOx-alumina catalysts have been studied and compared with Redox behaviors and catalytic properties in butane oxidation. X-ray diffraction, high-resolution transmission electron microscopy, and chemical differentiating dissolution were used for the catalysts characterization. Temperature-programmed reduction by hydrogen was employed to study the Redox properties. The catalyst Pt-MnOx-alumina has been shown to possess synergetic effects in the catalytic butane oxidation activity and reducibility by hydrogen as compared to alone Pt-alumina and MnOx-alumina samples. These effects were shown to be associated with modification of the imperfect Al3+-doped beta-Mn3O4 nanoscale particles and the Mn3+-doped alumina crystals by platinum ions as well as the intimate contact of 1-2 nm sized PtO2 particles with beta-Mn3O4 and manganese-alumina particles. It was found that Pt-precursors (such as H2PtCl6, H-2[Pt(OH)(6)], Pt(NO2)(2)(NH3)(2), [Pt(NH3)(4)]Cl-2), alumina phase type (gamma and chi) and temperature of the manganese-alumina activation (500 and 900 A degrees C) had a strong effect on the unique properties of the Pt-MnOx-alumina in butane oxidation and its reducibility. 

Hydrocarbon oxidation; Manganese oxides; Noble metal; Platinum; Synergetic effect