Simple molybdate selective oxidation catalysts containing excess MoO/sub 3/ for C/sub 4/ hydrocarbon oxidation to maleic anhydride

Technical Report · Tue Jan 01 04:00:00 EST 1985

OSTI ID:6187629

Ozkan, U S

In this research NiMoO/sub 4/ and CoMoO/sub 4/ selective oxidation catalysts with excess MoO/sub 3/ have been investigated in regard to their catalytic performance in C/sub 4/ hydrocarbon conversion to maleic anhydride. Routes have been established for the synthesis of pure molybdates; incorporation of excess MoO/sub 3/ into these catalysts have been accomplished using three different preparation techniques, namely, precipitation, solid state reaction and impregnation. Extensive characterization of the catalysts has been performed using complementary instrumentation techniques such as surface area measurements, x-ray fluorescence, x-ray diffraction, laser Raman spectroscopy, Raman microprobe spectroscopy, scanning electron microscopy, energy dispersive x-ray analyzer, and x-ray photoelectron spectroscopy. It has been shown that these catalysts exhibit a two-phase nature with distinct particles of NiMoO/sub 4/ and MoO/sub 3/ existing together. The formation of a solid solution or the formation of new nickel- (or cobalt-) molybdenum-oxygen compounds have been shown not to occur. Characterization investigations have indicated that a specific state of association of the particles was crucial: the surface of MoO/sub 3/ crystallites was covered or decorated with NiMoO/sub 4/. Kinetic investigations have been performed on these catalytic systems using a continuous, fixed bed integral reactor system for selective oxidation of C/sub 4/ hydrocarbons to maleic anhydride. Butene oxidation studies have shown that pure MoO/sub 3/ and pure NiMoO/sub 4/ are completely nonselective for maleic anhydride formation whereas catalysts which contain excess MoO/sub 3/ have a high selectivity for maleic anhydride which is accompanied by a sharp drop in CO/sub x/ selectivity. 101 references.

• Research Organization: Ames Lab., IA (USA)
• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 6187629
• Report Number(s): IS-T-1167; ON: DE85004793
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201 -- Chemical & Physicochemical Properties
400301* -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
ALKENES
ANHYDRIDES
BUTENES
CATALYSTS
CATALYTIC EFFECTS
CHEMICAL PREPARATION
CHEMICAL REACTIONS
COBALT COMPOUNDS
COHERENT SCATTERING
DATA
DIFFRACTION
ELECTRON MICROSCOPY
ELECTRON SPECTROSCOPY
EXPERIMENTAL DATA
HYDROCARBONS
INFORMATION
LASER SPECTROSCOPY
MICROSCOPY
MOLYBDATES
MOLYBDENUM COMPOUNDS
NICKEL COMPOUNDS
NUMERICAL DATA
ORGANIC COMPOUNDS
OXIDATION
OXYGEN COMPOUNDS
PACKED BED
PHOTOELECTRON SPECTROSCOPY
RAMAN SPECTROSCOPY
REFRACTORY METAL COMPOUNDS
SCANNING ELECTRON MICROSCOPY
SCATTERING
SPECIFICITY
SPECTROSCOPY
STRUCTURAL CHEMICAL ANALYSIS
SYNTHESIS
TRANSITION ELEMENT COMPOUNDS
X-RAY DIFFRACTION
X-RAY SPECTROSCOPY