Structure, thermal stability, and CO adsorption properties of Pd nanoparticles supported on an ultra-thin SiO2 film
2007 (English)In: Surface review and letters, ISSN 0218-625X, Vol. 14, no 5, 927-934 p.Article in journal (Refereed) Published
Nucleation, growth, and thermal stability of Pd particles vapor-deposited on an ultra-thin crystalline silica film grown on Mo(112) have been studied by scanning tunneling microscopy, X-ray photoelectron spectroscopy, infrared reflection absorption spectroscopy, and temperature-programmed desorption of CO. No preferential nucleation of Pd on the silica film is found at room temperature deposition: the hemispherical Pd nanoparticles are homogenously dispersed on the support at all coverages studied (0.01-1ML(mono layer)). The Pd particles are resistant toward sintering up to 700K as judged by STM; however, CO adsorption studies have revealed surface chemical modification at temperatures as low as 550K. Strong morphological changes are observed above 800K (ultimately resulting in elongated rectangular islands at similar to 1000 K), which is accompanied by strong alterations of CO adsorption properties. The results are rationalized in terms of Pd and Mo substrate interdiffusion at elevated temperatures, while the silica film basically preserves its structure.
Place, publisher, year, edition, pages
2007. Vol. 14, no 5, 927-934 p.
model catalysts; palladium silica; CO adsorption; thin oxide films; thermal stability
Other Physics Topics
IdentifiersURN: urn:nbn:se:kth:diva-49017DOI: 10.1142/S0218625X07010469ISI: 000251515400011OAI: oai:DiVA.org:kth-49017DiVA: diva2:459144
QC 201111292011-11-242011-11-242011-11-29Bibliographically approved