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The ability to stabilize very small Pt crystallites in supported-metal catalysts following harsh treatments is an important industrial problem. Here, we demonstrate that Pt particles can be maintained in the 1- to 2-nm range following multiple oxidation and reduction cycles at 1073 K when the particles are supported on 0.5-nm LaFeO3 films that have been deposited onto MgAl2O4 using atomic layer deposition. Characterization by scanning transmission electron microscopy suggests that when the catalyst is oxidized at 1073 K, the Pt crystallites are oriented with respect to the underlying LaFeO3. X-ray absorption spectroscopy also shows evidence of changes in the Pt environment. CO-oxidation rates for the reduced catalyst remain unchanged after five redox cycles at 1073 K. Epitaxial growth of Pt clusters and the consequent strong metal–support interaction between Pt and LaFeO3 are suggested to be the main reasons for the enhanced catalytic performances.

Hydrodeoxygenation (HDO) of m-cresol to produce toluene over carbon-supported Pt and Pt-WO x catalysts was studied. In stark contrast to Pt/C that exhibits only modest selectivity and low stability for this reaction, Pt-WO x /C was found to be unusually active and selective to toluene with greater than 94% selectivity to this product while exhibiting little to no deactivation under a wide range of reaction conditions. Reactivity studies in combination with density functional theory (DFT) calculations for the adsorption and reaction of m-cresol on structurally optimized WO x -decorated Pt(111) structures indicate that the HDO reaction on Pt-WO x /C proceeds via a direct hydrogenolysis of the C–O bond in m-cresol adsorbed on oxygen vacancy (or redox) sites on WO x species. The DFT results also indicate that Pt helps stabilize the WO x film while facilitating oxygen vacancy formation.

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