Enhanced activity of rare earth doped PtRu/C catalysts for methanol electro-oxidation

Interaction of oxygen with samarium on Al2O3 thin film grown on Ni3Al(111)

The interaction between oxygen and samarium (Sm) on the well-ordered thin Al2O3 film grown on Ni3Al(111) has been investigated by X-ray photoelectron spectroscopy and synchrotron radiation photoemission spectroscopy. At Sm coverage higher than one monolayer, exposure of oxygen to the Sm films at room temperature leads to the formation of both samarium peroxide (O2(2-)) states and regular samarium oxide (O(2-)) states. By contrast, when exposing O2 to Sm film less than one monolayer on Al2O3, no O2(2-) can be observed. Upon heating to higher temperatures, these metastable O2(2-) states dissociate, supplying active O atoms which can diffuse through the Al2O3 thin film to further oxidize the underlying Ni3Al(111) substrate, leading to the significant increase of the Al2O3 thin film thickness. Therefore, it can be concluded that Sm, presumably in its peroxide form, acts as a catalyst for the further oxidation of the Ni3Al substrate by supplying the active oxygen species at elevated temperatures.

Cu2O template synthesis of high-performance PtCu alloy yolk–shell cube catalysts for direct methanol fuel cells

Novel PtCu alloy yolk–shell cubes were fabricated via the disproportionation and displacement reactions in Cu₂O yolk–shell cubes, and they exhibit significantly improved catalytic activity and durability for methanol electrooxidation.

The Effect of PtRuIr Nanoparticle Crystallinity in Electrocatalytic Methanol Oxidation

Two structural forms of a ternary alloy PtRuIr/C catalyst, one amorphous and one highly crystalline, were synthesized and compared to determine the effect of their respective structures on their activity and stability as anodic catalysts in methanol oxidation. Characterization techniques included TEM, XRD, and EDX. Electrochemical analysis using a glassy carbon disk electrode for cyclic voltammogram and chronoamperometry were tested in a solution of 0.5 mol L^-1 CH₃OH and 0.5 mol L^-1 H₂SO₄. Amorphous PtRuIr/C catalyst was found to have a larger electrochemical surface area, while the crystalline PtRuIr/C catalyst had both a higher activity in methanol oxidation and increased CO poisoning rate. Crystallinity of the active alloy nanoparticles has a big impact on both methanol oxidation activity and in the CO poisoning rate.