On the Structure Insensitivity of Propane Total Oxidation over Pt/CeO₂: A Comparison between Single Atoms, Clusters and Nanoparticles

Abstract

A series of Pt/CeO2 catalysts with varied sizes of Pt domains are prepared and evaluated in propane total oxidation reaction, to investigate the structural sensitivity regarding the particle sizes and metal‐support interactions. Over Pt single atoms, clusters or nanoparticles (NP), the obtained similar turnover frequencies and apparent activation energies suggest the reaction is structure insensitive to the sizes of Pt domains. Nonetheless, detailed kinetic study reveals different adsorption behavior of reactants (C3H8 and O2) over these Pt species. Following a Langmuir‐Hinshelwood mechanism, C3H8 and O2 competitively adsorb on Pt surface. The adsorption of C3H8 and O2 on Pt single atom is much easier than on Pt nanoparticles due to its lower coordination. These findings provide experimental evidences for the reaction behavior of C3H8 oxidation over Pt/CeO2 catalysts, and lay a foundation for further understanding of the structure‐property relationship.

Tuning the Metal–Support Interaction by Modulating CeO2 Oxygen Vacancies to Enhance the Toluene Oxidation Activity of Pt/CeO2 Catalysts

“…No diffraction peaks of other phases were observed, indicating that supports still maintain the cubic fluorite structure with treatment. ICP-OES analysis (Table ) showed that Pt loads ranged from 0.70 to 0.73%, but no peaks of Pt 0 or PtO x species were found in the diffraction peaks (about 40°), suggesting that Pt species were loaded uniformly and highly dispersed on CeO 2 nanorods . According to Scherrer’s formula, the {111} diffraction peak of CeO 2 was calculated, as shown in Table .…”

“…ICP-OES analysis (Table 1) showed that Pt loads ranged from 0.70 to 0.73%, but no peaks of Pt 0 or PtO x species were found in the diffraction peaks (about 40°), suggesting that Pt species were loaded uniformly and highly dispersed on CeO 2 nanorods. 27 According to Scherrer's formula, the {111} diffraction peak of CeO 2 was calculated, as shown in Table1. It can be seen that the grain size of CeO 2 nanorods subjected to surface redox using chemical reagents did not show significant changes.…”

A review on the photochemical synthesis of atomically dispersed catalysts

“…4 The effect was later confirmed in other systems and was collectively termed as the ''size effect''. 5,6 One might naturally be curious about the extreme effects in downsizing the supported metal species and its impact on the catalytic performance, but the synthetic methods and characterization techniques in use at that time held back such a curiosity.…”