Most of the world's hydrogen supply is currently obtained by reforming hydrocarbons. 'Reformate' hydrogen contains significant quantities of CO that poison current hydrogen fuel-cell devices. Catalysts are needed to remove CO from hydrogen through selective oxidation. Here, we report first-principles-guided synthesis of a nanoparticle catalyst comprising a Ru core covered with an approximately ...

Extended x-ray absorption fine structure ~EXAFS! measurements of Co78Cr22 , Co86Cr12Ta2 , and Co86Cr12Pt2 films were made to investigate the local structure and chemistry around Ta and Pt atoms to determine their site distributions in these alloys. Comparisons between the measured data and data collected from experimental standards and calculated using theoretical EXAFS simulation codes indicat...

Using first principles quantum mechanics [nonlocal density functional theory (B3LYP)], we calculated the 13 most likely intermediate species for methanol oxidation on clusters of all 2nd and 3rd row Group VIII transition metals for all three likely binding sites (top, bridge, and cap). This comprehensive set of binding energies and structures allows a detailed analysis of possible reaction mech...

The CO tolerance mechanism of the hydrogen oxidation reaction was investigated on several highly dispersed carbon-supported nanocrystalline Pt and binary Pt alloys. For this purpose, current/potential behavior was derived from half-cells under actual proton exchange membrane fuel cell operating conditions and correlated with expressions derived from kinetic models. Kinetic analyses have shown t...

The use of Pt–Rh catalysts is central in a number industrial processes, and to explain their performance it essential have solid understanding nanoscopic surface structure. Here we scanning tunneling microscopy investigate the growth, elemental nanostructuring, reconstruction behavior various near-surface alloys (NSA) on fcc Rh(111) Pt(111). We document formation novel lamellar island atop Pt/R...

statement of problem: element release from dental casting alloys into the oral environment is of clinical concern and is considered to be a potential health problem to all patients. purpose: the aim of this study was to investigate the metallic ion release of four base metal alloys. materials and methods: two ni-cr (minalux and supercast) and two co-cr alloys (minalia and wironit) were examined...