CO Adsorption on Co(0001)-Supported Pt Overlayers

Abstract

the growth of Pt deposits on Co(0001) was followed by STM and XPS. The chemical reactivity of the resulting surface was checked by CO adsorption. Pt grows as dendritic islands on the Co terraces whereas forming stripes at the Co step edges.Annealing the sample has no apparent effect on the STM pictures. However, XPS suggests that a limited dilution of Pt in Co takes place. The adsorption of CO on the surface is drastically affected by the presence of Pt even for minute traces. The adsorption energy on the Pt areas is decreased by 40 %. The maximum coverage on the Co areas is also decreased. This indicates that Pt impurities diluted in Co have a high passivating power as a consequence of the induced electronic changes.

Adhesion and bonding of Pt/Ni and Pt/Co overlayers: Density functional calculations

“…electronic Indeed, according to our observations presented in previous works[2,3,17,19,20] and in the literature[21], CO adsorbs much strongly on Pt(111) pure than on a monolayer of Pt on Ni(111) and Co(0001). A decrease in the CO adsorption energy has also been observed for the Pt/Ta, Pt/Zn, Pt/W and Pt/Mo systems (see Fig.34of Ref.…”

Adsorption and Dissociation of CO on a Fe−Co Alloy (110) Surface: A Theoretical Study

“…Many theoretical investigations previously reported in the literature have focused on merely the CO adsorption on pure metal surfaces. − ,− Similar studies concerning the systems of supported and bimetallic alloys on the other hand have recently become popular because of the unique catalytic properties these alloys exhibit compared to the pure components. ,− For instance, the doping of Pt on Ni can significantly enhance the aromatization of linear hexane, the activity which is absent in the case of pure Ni, while replacing Pt with Au suppresses the surface coating of Ni by graphite during the steam-reforming of n -butane . The existence of such distinctive properties are generally attributed to the intermetallic interaction of the constituents.…”

Nanoscale architecture of ceria-based model catalysts: Pt–Co nanostructures on well-ordered CeO2(111) thin films

“…Hence, if the first Pt ML has a high resistance to alloy formation, a growth of a second ML destabilizes the Pt films and facilitates alloying. However, a limited Pt-Co intermixing in the first Pt ML was also reported [48,49]. In fact, based on the Pt-Co phase diagram [44], the formation of a solid solution is also favorable during stepwise deposition of Pt onto Co nanoparticles at 300 K. In general, the association of the Pt-Co interface contribution with a minor Pt-Co intermixing at 300 K appears reasonable for both Pt@Co and Co@Pt nanostructures.…”