• Nielsen, Monia R.
• Damsgaard, Christian D.
• Pruessmann, Tim
• Sheppard, Thomas L.
• Smitshuysen, Thomas Erik Lyck
• Chorkendorff, Ib
• Zimina, Anna
• Grunwaldt, Jan-Dierk

Abstract

A screening study of the catalytic performance of ternary alloy nanoparticles containing nickel, iron and gallium supported on silica for methanol synthesis from CO$_{2}$ and H$_{2}$ was performed. Catalysts were prepared by incipient wetness impregnation and subsequently reduced in H$_{2}$ before catalytic testing. Ni$_{2}$FeGa 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/Al$_{2}$O$_{3}$/MgO at low reaction temperatures and pressure. Extensive in situ characterisation using environmental TEM, in situ XRD and in situ EXAFS of the formation of the Ni$_{2}$FeGa catalyst explains an optimal reduction temperature of 550 °C: warm enough that the three atomic species will form an alloy while cold enough to prevent the catalyst from sintering during the formation.

Topics

• nanoparticle
• nickel
• x-ray diffraction
• transmission electron microscopy
• iron
• sintering
• Gallium
• extended X-ray absorption fine structure spectroscopy