Improved NO–CO reactivity of highly dispersed Pt particles on CeO2 nanorod catalysts prepared by atomic layer deposition†
Highly dispersed platinum (Pt) nanoparticles are deposited on CeO2 nanorods via atomic layer deposition (ALD) to improve the catalytic activity towards the NO–CO reaction. For comparison, CeO2 nanosphere and CeO2 nanorod loaded Pt nanoparticle catalysts fabricated by ALD and incipient wetness impregnation (IWI) are studied. The size distribution of Pt nanoparticles of Pt/CeO2 nanosphere (Pt/CeO2-NS) and Pt/CeO2 nanorod (Pt/CeO2-NR) catalysts prepared by ALD is quite narrow and uniform (3.05 ± 0.42 nm for Pt/CeO2-NSs, and 3.05 ± 0.38 nm for Pt/CeO2-NRs) compared to that of the PtIWI/CeO2-NS catalyst prepared by incipient wetness impregnation. The combination of XPS, H2-TPR, XAFS and in situ DRIFTS characterization techniques confirms that the strong interaction between Pt nanoparticles and CeO2 nanorods leads to the decrease of the CO poisoning effect on Pt and activation of oxygen around the interfaces. As a result, the full conversion of NO takes place at a relatively low temperature of ∼200 °C, revealing that the activity of the ALD prepared Pt/CeO2-NR catalyst is greatly enhanced.