Compounds of molybdenum and tungsten with high specific surface area:

Journal Article · Tue Oct 01 04:00:00 EDT 1985 · J. Solid State Chem.; (United States)

DOI:https://doi.org/10.1016/0022-4596(85)90301-9· OSTI ID:6120271

Volpe, L; Boudart, M

Temperature-programmed reaction between MoO/sub 3/ or WO/sub 3/ with NH/sub 3/ provides a new way to prepar Mo/sub 2/N and W/sub 2/N powders with specific surface areas as high as 220 and 91 m/sup 2/g/sup -1/, respectively, corresponding to 3- to 4-nm crystallites. The transformation of MoO/sub 3/ platelets is topotactic in the sense that (100) planes of Mo/sub 2/N are parallel to (010) planes of the MoO/sub 3/. As the MoO/sub 3/ reacts with NH/sub 3/, it passes through an oxynitride intermediate with changing bulk structure, increasing surface area, and decreasing oxidation state of the metal. The product consists of highly porous nitride platelets, pseudomorphous with the original MoO/sub 3/.

• Research Organization: Department of Chemical Engineering, Stanford University, Stanford, CA
• OSTI ID: 6120271
• Journal Information: J. Solid State Chem.; (United States), Journal Name: J. Solid State Chem.; (United States) Vol. 59:3; ISSN JSSCB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201* -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
360202 -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
AMMONIA
AMORPHOUS STATE
CHALCOGENIDES
CHEMICAL PREPARATION
CHEMICAL REACTIONS
CRYSTAL-PHASE TRANSFORMATIONS
HYDRIDES
HYDROGEN COMPOUNDS
MATERIALS
MOLYBDENUM COMPOUNDS
MOLYBDENUM NITRIDES
MOLYBDENUM OXIDES
NITRIDES
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
OXIDATION
OXIDES
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
PNICTIDES
POROUS MATERIALS
POWDERS
REFRACTORY METAL COMPOUNDS
SURFACE PROPERTIES
SYNTHESIS
TRANSITION ELEMENT COMPOUNDS
TUNGSTEN COMPOUNDS
TUNGSTEN NITRIDES
TUNGSTEN OXIDES