ОКСИД ВИСМУТА ЖЕЛЕЗА МОЛИБДЕНА

Description

Bismuth iron molybdenum oxide Bi3FeMo2O12 is a complex mixed oxide of bismuth, iron and molybdenum, an industrial catalyst for propylene ammoxidation. CAS 59393-06-5.

Basic Attributes

• CAS No: 59393-06-5
• Chemical formula: Bi3FeMo2O12
• Molecular weight: 1066.66
• Exact weight: 1070.63000
• PSA Specifications: 165.64000
• XLogP3: -1.17610

Synonyms

Bismuth iron molybdate; molybdenum iron bismuth oxide; bismuth-iron-molybdenum oxide, 99% (metal base).

Substance class and mechanism of action

Catalysts based on bismuth, iron and molybdenum oxides belong to the classical system for the selective oxidation and ammoxidation of olefins, developed by SOHIO in 1959 for the production of acrolein and acrylonitrile from propylene. Bismuth molybdate acts as the main active site responsible for the activation of the allylic hydrogen of propylene and the subsequent insertion of oxygen or ammonia, while the addition of iron stabilizes the catalyst during the reaction and increases the yield of target products by improving the redox cycle between iron and molybdenum centers of different valences.

Scope of application

A key industrial application is a catalyst for the ammoxidation of propylene in the presence of ammonia and oxygen (air) at elevated temperatures for the large-scale production of acrylonitrile, a key monomer for the production of acrylic fibers, rubbers and ABS plastics. A related system is also used for the oxidation of propylene to acrolein. The industrial use of catalysts of this composition is confirmed by numerous patents and covers large-scale installations with fluidized bed reactors.

Storage

Store in a dry place in a tightly closed container, avoid dust formation when working with catalyst powder. The ratio of bismuth, iron and molybdenum in industrial catalyst formulations is selected experimentally for a specific installation, often supplementing the composition with promoters - cobalt, nickel, potassium - to further increase selectivity for acrylonitrile and suppress side reactions of complete oxidation of propylene to carbon dioxide. The service life of an industrial catalyst on a bismuth-molybdenum-iron carrier is calculated in years of continuous operation in a fluidized bed reactor, after which the activity is partially restored by thermal regeneration or the batch of catalyst is replaced with a fresh load without stopping the entire production line. The PSA value of 165.64000 and XLogP3 -1.17610 are given as reference parameters for the molecular structure of the catalyst; in practice, activity and selectivity are assessed experimentally based on the yield of the target acrylonitrile in a laboratory or pilot reactor before scaling up the technology. Synonyms for the compound found in supplier catalogs: bismuth iron molybdate, bismuth iron molybdenum oxide, bismuth-iron molybdenum oxide (99%, metal base).