Multiscale Approach to the Dissociative Adsorption of Oxygen on a Highly Dispersed Platinum Supported on γ-Al₂O₃

Abstract

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Effect of the Pt Precursor and Loading on the Structural Parameters and Catalytic Properties of Pt/Al2O3

“…Local changes in the electron density of Pt 0 depend on the reactivity of Pt with O and reactants, as well as the degree of coverage of O, which is controlled by the size and morphology of the Pt NPs. A modification of the support charge, according to the type of metal precursor, could be reflected in the morphology of x PtAl precursors and in the electronic and geometric properties of the supported metal, which shows high reactivity with oxygen . Considering that oxygen interacts with the surface of the Pt core and that the Pt−O bond involves donation from the d orbital of Pt to p x of oxygen, it is expected that the Pt−O bond length (R Pt‐O ) should reflect the local electron density of Pt sites at the surface.…”

Atomistic Models for Highly‐Dispersed PtSn/γ‐Al2O3 Catalysts: Ductility and Dilution Affect the Affinity for Hydrogen

“…As a second perspective to this work, accounting for the presence of these oxidized Sn species will be necessary in the future to provide a more realistic description of the system. The reduced systems simulated here can be a good starting point for such investigation, in the spirit of previous work done for the description of oxidized forms of supported platinum …”

“…The reduced systems simulated here can be a good starting point for such investigation, in the spirit of previous work done for the description of oxidized forms of supported platinum. [24]…”

“…Supported Pt x Sn 13‐x clusters (0≤x≤13) were modeled, using the dehydrated γ‐Al 2 O 3 (100) surface model described previously . Indeed, from previous studies about monometallic or bimetallic catalysts, models involving the γ‐Al 2 O 3 (100) dehydrated surface already provided fruitful detailed information. Moreover, this surface exhibits pentacoordinated Al 3+ ions, which were experimentally suggested to stabilize Pt−Sn clusters efficient for propane dehydrogenation .…”

“…Significant amount of work has been devoted so far for the proposal of relevant dispersed monometallic Pt/Al 2 O 3 models, particularly in the case of the gamma polymorph of alumina . The ductility of small platinum clusters (typically, Pt 13 ) appears to be very strong, in the presence of hydrogen, oxygen and hydrocarbons despite the interaction with a support. Moreover, it was shown that Pt 13 clusters exhibit a higher adsorption capacity than the infinite Pt(111) surface .…”