cs9b04330_si_001.pdf (498.97 kB)
Relationship between Atomic Scale Structure and Reactivity of Pt Catalysts: Hydrodeoxygenation of m‑Cresol over Isolated Pt Cations and Clusters
journal contribution
posted on 2019-12-16, 05:32 authored by Joaquin Resasco, Feifei Yang, Tong Mou, Bin Wang, Phillip Christopher, Daniel E. ResascoAtomically dispersed late transition-metal cations have
attracted
significant attention as next-generation heterogenous catalysts. However,
relationships between the catalytic behavior of atomically dispersed
metal cations and active sites on metal nanoparticles have been difficult
to establish, in large part because of the difficulty in characterizing
the local atomic structure of these metal species. Here, we use the
hydrodeoxygenation (HDO) of m-cresol, a model bio-oil
compound, to understand relationships between metal structure and
reactivity down to the limit of atomically dispersed active sites.
Through a combination of kinetic studies, spectroscopic characterization,
and density functional theory calculations, we find that isolated
Pt cations supported on TiO2 are significantly less active
than small Pt clusters for m-cresol HDO due to their
lower activity for hydrogen dissociation and their weaker interaction
with m-cresol. We demonstrate that m-cresol HDO reaction kinetics are particularly sensitive to the active
Pt structure, suggesting that the catalytic reactivity can be a more
reliable indicator of catalyst structure than commonly used characterization
approaches. These findings provide insights into the ability of isolated
Pt cations to catalyze elementary processes critical for hydrogenation
catalysis.