27 research outputs found
Optimizing Ni-Fe-Ga alloys into NiFeGa for the hydrogenation of CO into methanol
A screening study of the catalytic performance of ternary alloy nanoparticles containing nickel, iron and gallium supported on silica for methanol synthesis from CO and H was performed. Catalysts were prepared by incipient wetness impregnation and subsequently reduced in H before catalytic testing. NiFeGa showed the best performance of the tested catalysts in terms of methanol yield. An optimization of the preparation was done to improve activity and selectivity, reaching a performance close to that of commercially available Cu/ZnO/AlO/MgO at low reaction temperatures and pressure. Extensive inâ
situ characterisation using environmental TEM, inâ
situ XRD and inâ
situ EXAFS of the formation of the NiFeGa catalyst explains an optimal reduction temperature of 550â°C: warm enough that the three atomic species will form an alloy while cold enough to prevent the catalyst from sintering during the formation
Comparative genomics and genome biology of Campylobacter showae
We thank the Garrett and Huttenhower laboratories for useful discussions. This work was supported by a Fulbright Scholarship to GH, an NHS Grampian Endowment grant fund to I.M. and G.H., a CSO clinical academic fellowship to R.H. (CAF/08/01). RH is supported by an NHS Research Scotland Career Researcher Fellowship. NIH NIDDK grant R24DK110499 to CH, and NSF grant DBI-1053486 to CH.Peer reviewedPublisher PD
Identification of Novel Genetic Loci Associated with Thyroid Peroxidase Antibodies and Clinical Thyroid Disease
Peer reviewe
Competing oxidation mechanisms in Cu nanoparticles and their plasmonic signatures
Chemical reactions involving nanoparticles often follow complex processes. In this respect, real-time probing of single nanoparticles under reactive conditions is crucial for uncovering the mechanisms driving the reaction pathway. Here, we have captured in situ the oxidation of single Cu nanoparticles to unravel a sequential competitive activation of different mechanisms at temperatures 50-200 degrees C. Using environmental scanning transmission electron microscopy, we monitor the evolution of oxide formation with sub-nanometre spatial resolution, and show how the prevalence of oxide island nucleation, Cabrera-Mott, Valensi-Carter and Kirkendall mechanisms under different conditions determines the morphology of the particles. Moreover, using in situ electron energy-loss spectroscopy, we probe the localised surface plasmons of individual particles during oxidation, and with the aid of finite-difference time-domain electrodynamic simulations investigate the signature of each mechanism in their plasmonic response. Our results shed light on the rich and intricate processes involved in the oxidation of nanoparticles, and provide in-depth insight into how these processes govern their morphology and optical response, beneficial for applications in catalysis, sensing, nanomedicine and plasmonics