Structure and chemisorptive properties of the Pt3Ti surface

CO tolerance of ordered intermetallic phases

“…The fact that some dissociative adsorption of CO has been previously found on Pt 3 Ti (1 1 1) and (1 0 0) and attributed to CO adsorbed on Ti [2], indicates that the oxidation of CO to CO 2 is only due to CO previously adsorbed on Pt atoms. It is interesting to note that AES studies have shown that the adsorption of CO on polycrystalline Pt 3 Ti is purely non-dissociative [3] (that is, strictly molecular).…”

“…Since Blyholder proposed a simple model to explain the chemisorption of CO on transition metals [1], extensive experimental and computational studies have been carried out over the years on polycrystalline and single crystal bulk materials, and more recently on nanoparticles. Numerous surface sensitive techniques such as thermal desorption and Auger electron spectroscopy (AES) [2,3], low energy electron diffraction [4], X-ray scattering [5,6], infrared spectroscopy [7][8][9], scanning tunneling microscopy [10] as well as electrochemical [6,[11][12][13][14] techniques have been used to gain insight on CO adsorption and oxidation.…”

Density Functional Study on the Interaction of Hydrogen with Pt3Ti(111)

“…In this phenomenon, Pt catalyst supported on TiO 2 showed a severe decrease (to near zero) in the chemisorption of hydrogen and carbon monoxide as the temperature is increased to 5009 C. This observation was ascribed to the formation of Pt 3 Ti compound, whose formation is themodynamically favored compared to other Pt-Ti compounds 1) . Bardi and co-workers 2) then studied the H 2 (and CO) chemisorption on a polycrystalline and singlecrystal surfaces of this compound using AES and TDS, and found essentially no chemisorption for H 2 at room temperature. However, it was reported that this compound shows increased catalytic activity compared to Pt for the electrolytic reduction of oxygen to water in acid fuel cells 3) which would imply that this compound may exhibit greater catalytic activity in dissociating H 2 .…”

Random alloy and intermetallic nanocatalysts in fuel cell reactions

“…Bardi and co-workers reported that the CO adsorption energy on the pure Pt surface was 5 times higher than that on the Pt 3 Ti surface, implying that Pt 3 Ti may have an increased CO poisoning tolerance. 90 DiSalvo et al synthesized fcc-Pt 3 Ti samples with a smaller size (about 3 nm) in tetrahydrofuran; then they were transformed into the intermetallic compound with a large size (∼37 nm) by annealing above 400°C. 91 CO stripping experiment shows that the CO oxidation peaks of Pt 3 Ti nanoparticles are much weaker than those of pure Pt and PtRu samples, suggesting that the CO affinity of Pt 3 Ti catalysts is very low and the catalyst surface is difficult to poison with CO.…”