Strong synergism between gold and manganese in an Au–Mn/triple-oxide-support (TOS) oxidation catalyst

• Gold deposition precipitated on Mn-impregnated triple oxide support (TOS).
• Au–Mn/TOS catalyst exhibited high catalytic activity in propane oxidation.
• Strong synergism exists between Mn and Au in the Au–Mn/TOS catalyst.
• Interaction of Au and Mn lead to formation of the compounds Au2Mn and Au5Mn2.
• Combine action of Au and Mn to attract non-stoichiometric and lattice oxygen.

A strong synergism between Au and Mn substantially increased the catalytic activity of the Au–Mn/TOS catalyst for the complete propane oxidation as compared to the activity of mono metal Au/TOS and Mn/TOS catalysts. The high activity of Au–Mn/TOS catalyst is a result of the formation of Au2Mn or Au5Mn2 phases and enhanced mobility of the oxygen in the support oxides. XPS, TPR, TEM and XRD studies were used to characterise the catalysts. Based on the results, a possible mechanism for the participation of the non-stoichiometric and lattice oxygen is also proposed. It is suggested that a joint effect of the Au and Mn increased the non-stoichiometric and lattice oxygen mobility of the Au–Mn/TOS catalyst, potentially being dominated by Mn.

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