Iron-molybdenum composite metal oxide catalyst and preparation method and application thereof

Abstract

The invention discloses an iron-molybdenum composite metal oxide catalyst and a preparation method and application thereof. Precursors of iron oxide and molybdenum oxide of different amounts are impregnated on an alumina carrier together, and a 1MoxFeAl catalyst is obtained after drying, roasting, tableting and screening, wherein the supporting amount of iron is 3-40%, x represents the molar ratioof iron and molybdenum, and the molar ratio range is 3-15. The catalyst can simultaneously achieve the high conversion rate of propane and the high selectivity of propylene, meanwhile the introduction of lattice oxygen in the catalyst breaks thermodynamic equilibrium and improves the efficiency of the catalyst. After the propane passes through a catalyst bed layer, metal oxide in a high valence state is reduced, the lattice oxygen is lost, the state becomes a low valence state, and catalytic activity is lost. After N2 purification, the reacted catalyst is re-oxidized to be in a high-valence state by introducing air at the reaction temperature, lattice oxygen is supplemented, and g the capacity of oxidative dehydrogenation of propane is regained.

Description

technical field [0001] The invention relates to a composite metal oxide dehydrogenation catalyst, specifically including the preparation of a loaded iron-molybdenum composite metal oxide catalyst and its application in a chemical chain propane dehydrogenation process. Background technique [0002] Propylene is an important chemical raw material, mainly used in the production of polypropylene, acrylonitrile, propylene oxide and other chemical products. At this stage, the production capacity of propylene is growing rapidly, but the main source is light oil cracking and heavy oil catalysis A by-product of the cracking process. Shale gas is rich in a large amount of low-carbon alkanes. As an effective way to rationally utilize low-value saturated alkanes to produce high-value-added corresponding alkenes, alkane dehydrogenation technology has received extensive attention in recent years. [0003] Taking propane direct dehydrogenation (PDH) as an example, industrial catalysts mai...

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Problems solved by technology

Oxidative dehydrogenation (ODH) is another production process of propane to propylene. Although ODH is an exothermic reaction, it breaks the thermodynamic limit of the reaction, and the reaction temperature is lower, which also reduces the influence of carbon deposition on the catalyst. However, under the action of molecular oxygen, propylene tends to undergo further C-C cleavage, complete oxidation to produce carbon oxides, the selectivity of propylene is low, and the mixture of alkanes and oxygen has potential safety hazards, which increases the difficulty of industrialization

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