Niobium tungsten oxides are currently probed as promising candidates for applications as electrochemical and thermoelectric materials. The manifold structural chemistry in the pseudo-binary system Nb2O5/WO3, however, has puzzled solid state chemists and crystallographers since the early 1960s. Based on the ReO3 type with corner-sharing octahedra MO3 (M = Nb,W), various octahedral frameworks cover oxygen:metal ratios in the range 2.5 = O/ΣM = 3.0, i.e. from Nb2O5 (left) to WO3 (right,
see scheme). The review begins with an overview about synthesis and structures of the existing phases comprising structures of the
block-type and related to the tetragonal tungsten bronzes. Derivatives of a certain phase can be prepared by the substitution of Nb5+ according to Nb5+ = M4+ + W6+ leading to isostructural solid solution series. Aspects of the structural characterization by X-ray diffraction and by various electron microscopy methods are discussed before the listing of physical properties and potential applications closes this overview.
The Complex Crystal Chemistry of Niobium Tungsten Oxides
F. Krumeich, Chem. Mater. 2022, 34, 911-934 DOI
Environment, Sustainability and Energy
Division Horizon Prize: John Jeyes Award
For the discovery, fundamental
understanding, and technical development of a novel catalytic
technology for the recycling of carbon dioxide to produce
sustainable methanol (RCS).
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