Individual Fe−Co Alloy Nanoparticles on Carbon Nanotubes: Structural and Catalytic Properties

• Published in: Nano letters Vol. 8; no. 9; pp. 2738 - 2743
• Main Authors: Zhang, Jian, Müller, Jens-Oliver, Zheng, Weiqing, Wang, Di, Su, Dangsheng, Schlögl, Robert
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01.09.2008
• Subjects: Catalytic methods; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Materials science; Methods of nanofabrication; Nanocrystalline materials; Nanoscale materials and structures: fabrication and characterization; Nanotubes; Physics; Scanning electron microscopy; Carbon nanotubes; Iron alloys; XRD; Dispersive spectrometry; Synergism; Nanoparticles; Ammonia; Transmission electron microscopy; EEL spectroscopy; Alloying; Catalysis; Nanostructured materials; Cobalt alloys; X-ray photoelectron spectra
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/nl8011984

We report the synthesis, characterization, and catalytic performance of Fe−Co alloy nanoparticles inside the tubular channel of carbon nanotubes. The homogeneous distributions of Fe and Co in the isolated nanoparticles were evidenced confidentially by bulk and surface structural and compositional characterizations, that is, scanning electron microscopy, high-resolution transmission electron microscope in combination with elemental mapping by energy dispersive X-ray spectroscopy and electron energy-loss spectroscopy, powder X-ray diffraction, and X-ray photoelectron spectroscopy. We also demonstrate for the first time an unusual synergism in alloy catalysis. The alloy nanoparticles with widely varying Co/Fe ratio are kept as active as Co for the H2 production from NH3 decomposition. The stability of Co was significantly improved by alloying with Fe. We expect our experimental method to be a general approach to elucidate the synergism phenomenon in alloy catalysis.