Catalytic Oxidation of Carbon Monoxide on a Curved Pd Crystal: Spatial Variation of Active and Poisoning Phases in Stationary Conditions.
Frederik SchillerMax IlynVirginia Pérez-DiesteCarlos Miguel Santacruz-EscuderoCristián Huck-IriartNerea Ruiz Del ArbolBenjamin HagmanLindsay R MerteFlorian BertramMikhail ShipilinSara BlombergJohan GustafsonEdvin LundgrenJosé Enrique OrtegaPublished in: Journal of the American Chemical Society (2018)
Understanding nanoparticle catalysis requires novel approaches in which adjoining crystal orientations can be studied under the same reactive conditions. Here we use a curved palladium crystal and near-ambient pressure X-ray photoemission spectroscopy to characterize chemical species during the catalytic oxidation of CO in a whole set of surfaces vicinal to the (111) direction simultaneously. By stabilizing the reaction at fixed temperatures around the ignition point, we observe a strong variation of the catalytic activity across the curved surface. Such spatial modulation of the reaction stage is straightforwardly mapped through the photoemission signal from active oxygen species and poisoning CO, which are shown to coexist in a transient regime that depends on the vicinal angle. Line-shape analysis and direct comparison with ultrahigh vacuum experiments help identifying and quantifying all such surface species, allowing us to reveal the presence of surface oxides during reaction ignition and cooling-off.
Keyphrases
- solid state
- high resolution
- electron transfer
- air pollution
- hydrogen peroxide
- genetic diversity
- particulate matter
- magnetic resonance
- magnetic resonance imaging
- computed tomography
- nitric oxide
- liquid chromatography
- dna methylation
- cystic fibrosis
- pseudomonas aeruginosa
- visible light
- crystal structure
- mass spectrometry
- staphylococcus aureus
- subarachnoid hemorrhage