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CN-122010189-A - Preparation method of cobalt molybdenum oxide catalyst and method for preparing propylene by catalyzing oxidative dehydrogenation of propane

CN122010189ACN 122010189 ACN122010189 ACN 122010189ACN-122010189-A

Abstract

The invention discloses a cobalt molybdenum oxide catalyst, a preparation method thereof and a method for preparing propylene by catalyzing oxidative dehydrogenation of propane; the preparation method comprises the steps of (1) preparing a cobalt nitrate hexahydrate aqueous solution, (2) adding sodium molybdate dihydrate into the cobalt nitrate hexahydrate aqueous solution, stirring for 30min at normal temperature, (3) dropwise and slowly dropwise adding the mixed solution onto AlOOH powder and stirring, 4) putting the mixed paste into a ball milling tank for ball milling for 4h, 5) centrifugally drying to obtain a solid product, and (6) calcining the solid product at 500 ℃ for 4h to obtain a finished product, and belongs to the technical fields of thermocatalytic materials and environmental protection.

Inventors

  • WANG XUYU
  • JI HONGBING
  • JI FENGYU

Assignees

  • 江苏科技大学
  • 江苏中江材料技术研究院有限公司

Dates

Publication Date
20260512
Application Date
20260326

Claims (10)

  1. 1. The preparation method of the cobalt molybdenum oxide catalyst is characterized by comprising the following steps in sequence: (1) Preparing a cobalt nitrate hexahydrate aqueous solution by using cobalt nitrate hexahydrate; (2) Adding sodium molybdate dihydrate into cobalt nitrate hexahydrate water solution, and stirring for 30min at normal temperature; (3) Dropwise and slowly dripping the mixed solution onto AlOOH powder, and stirring; (4) Putting the mixed paste into a ball milling tank for ball milling for 4 hours; (5) Centrifugal drying to obtain a solid product; (6) Calcining the solid product in air atmosphere to obtain the final product, which belongs to the technical field of thermocatalytic materials and environmental protection.
  2. 2. The method for preparing a cobalt molybdenum oxide catalyst according to claim 1, wherein the aqueous cobalt nitrate hexahydrate solution in step (1) is obtained by adding 0.68mmol of cobalt nitrate hexahydrate to 25mL of water.
  3. 3. The method for preparing a cobalt molybdenum oxide catalyst according to claim 1, wherein the mixed solution in the step (2) is obtained by adding 0.34mmol of sodium molybdate dihydrate to an aqueous cobalt nitrate hexahydrate solution.
  4. 4. The method for preparing a cobalt molybdenum oxide catalyst according to claim 1, wherein the ratio of the mixed solution to the powder in the step (3) is 1 ml/1 g.
  5. 5. The method for preparing a cobalt molybdenum oxide catalyst according to claim 1, wherein the ball mill parameter in the step (4) is 500 r/min for 4 hours.
  6. 6. The method for preparing cobalt molybdenum oxide catalyst according to claim 1, wherein the centrifugation parameter in the step (5) is 10000 r/min for 5min, the washing condition is deionized water washing 1 time, and the drying temperature is 60 ℃ and the time is 12h.
  7. 7. The method for preparing a cobalt molybdenum oxide catalyst according to claim 1, wherein the calcination temperature in step (6) is 500 ℃ and the calcination time is 4 hours.
  8. 8. A cobalt molybdenum oxide catalyst prepared by the method of any one of claims 1-7.
  9. 9. The method for preparing propylene by catalytic oxidative dehydrogenation of propane by using the cobalt molybdenum oxide catalyst according to claim 8 is characterized in that the catalytic conditions are that the raw material gas comprises 5% of propane, 4% of oxygen and the balance gas is nitrogen, the airspeed is 5200 mL/(g.h), and the reaction temperature is 150-210 ℃.
  10. 10. The cobalt molybdenum oxide catalyst provided by the invention is applied to the field of thermocatalysis. The catalyst has certain catalytic efficiency on monomer micromolecular organic matters, and can be used for degrading common organic pollutants in air.

Description

Preparation method of cobalt molybdenum oxide catalyst and method for preparing propylene by catalyzing oxidative dehydrogenation of propane Technical Field The invention relates to a catalyst, in particular to a cobalt molybdenum oxide catalyst, and also relates to a preparation method of the cobalt molybdenum oxide catalyst, belonging to the technical fields of thermal catalytic materials and environmental protection. Background Propylene is a key raw material for three major synthetic materials, namely plastics, rubber and chemical fibers, and the market demand for derivatives thereof continues to grow rapidly. Currently, the industrial production of propylene mainly relies on steam cracking of petroleum byproducts (such as naphtha and light diesel) and fluid catalytic cracking processes, as well as propane direct dehydrogenation processes. Along with the reduction of the exploitation cost of alkane in shale gas, the Oxidative Dehydrogenation (ODHP) of propane is receiving attention increasingly because of the advantages of low energy consumption, less carbon deposit, obvious thermodynamic advantage and the like. However, inhibiting deep oxidation, increasing catalyst activity and olefin selectivity remain key challenges to be addressed in the industry. In ODHP catalyst systems, transition metal oxides predominate, and include mainly types of V-based, cr-based, ni-based, mo-based, and rare earth-based. Nickel-based and vanadium-based catalysts, while achieving higher propylene selectivity, generally require higher reaction temperatures (> 500 ℃) and consume greater energy. In recent years cobalt-based and molybdenum-based catalysts have also demonstrated unique advantages in ODHP reactions. Cobalt-based catalysts, because of their rich oxygen species and regulatable redox properties, are distinguished by promotion of propane C-H bond activation, and tend to be accompanied by a lower tendency to complete oxidation. Molybdenum-based catalysts are known for their excellent propylene selectivity and resistance to carbon deposition. The construction of a multi-metal synergistic catalytic system by combining the low-temperature activation characteristic of cobalt and the selectivity advantage of molybdenum has become one of the important directions of the design of the current ODHP catalyst, so that the molybdenum is doped in the cobalt oxide catalyst to prepare a cobalt-molybdenum oxide catalyst, and the low-temperature catalytic oxidative dehydrogenation of propane to prepare propylene is realized Disclosure of Invention In view of the above problems, the present invention aims to provide a method for preparing a cobalt molybdenum oxide catalyst and to provide a high selectivity for preparing propylene by oxidative dehydrogenation of propane at low temperature based on the problems faced by transition metal-based catalysts. In order to achieve the above object, the first technical solution provided by the present invention is as follows: the preparation method of the cobalt molybdenum oxide catalyst sequentially comprises the following steps: (1) Preparing a cobalt nitrate hexahydrate aqueous solution by using cobalt nitrate hexahydrate; (2) Adding sodium molybdate dihydrate into cobalt nitrate hexahydrate water solution, and stirring for 30min at normal temperature; (3) Dropwise and slowly dripping the mixed solution onto AlOOH powder, and stirring; (4) Putting the mixed paste into a ball milling tank for ball milling for 4 hours; (5) Centrifugal drying to obtain a solid product; (6) Calcining the solid product in air atmosphere to obtain the final product, which belongs to the technical field of thermocatalytic materials and environmental protection. Further, in the preparation method of the cobalt molybdenum oxide catalyst, the cobalt nitrate hexahydrate aqueous solution in the step (1) is obtained by adding 0.68mmol of cobalt nitrate hexahydrate into 25mL of water. In the preparation method of the cobalt molybdenum oxide catalyst, the mixed solution in the step (2) is obtained by adding 0.34mmol of sodium molybdate dihydrate into a cobalt nitrate hexahydrate aqueous solution. Further, in the preparation method of the cobalt molybdenum oxide catalyst, the ratio of the mixed solution to the powder in the step (3) is 1ml to 1g. Further, in the preparation method of the cobalt molybdenum oxide catalyst, the parameters of the ball mill in the step (4) are 500 r/min, and the time is 4 hours. Further, in the preparation method of the cobalt molybdenum oxide catalyst, the centrifugal parameter in the step (5) is 10000 r/min, the time is 5min, the washing condition is that deionized water is washed for 1 time, and the drying temperature is 60 ℃ and the time is 12h. Further, in the preparation method of the cobalt molybdenum oxide catalyst, the calcination temperature in the step (6) is 500 ℃ and the calcination time is 4 hours. The second technical scheme provided by the invention is that the cobalt-molybdenum ox