Co Deposited Vanadium Tungsten Nanocrystalline Preparation

Selective Catalytic Reduction (SCR) is a process for the reduction of NO_x from the atmosphere to N₂ and H₂O under the action of catalysts. At present, in most thermal power plants in China, W-V-Ti composite material is the main catalyst treatment material, in which titanium acts as a carrier, vanadium acts as an activator and tungsten acts as a catalyst.

It is found that the photocatalytic properties of nano-scale vanadium pentoxide and tungsten oxide co-deposited can play a better synergistic role; nano-materials can improve the properties of bulk materials or produce new properties which block materials do not have because of their micro-size effect and special morphology.

In order to solve the problems of difficult realization, low repetition rate, complex preparation process and rigorous equipment requirements of the prepared cubic nanoparticles, a hydrothermal method for preparing vanadium tungsten pentoxide / tungsten oxide co-deposited vanadium tungsten nanocrystalline was proposed.

1.Preparation of vanadium source solution: 5 mol vanadium sulfate was dissolved in 25 mL deionized water to obtain vanadium sulfate solution; 50 mL anhydrous ethanol was added into vanadium sulfate solution, and then magnetic stirring speed was 900 r/min for 15 minutes to obtain vanadium source solution.

2.Preparation of tungsten source solution: 10 mL sodium tungstate solution with 1 mol/L concentration and 10 mL sulfuric acid with 98% mass fraction were mixed, then dripped with 0.6 mL hydrogen peroxide solution with 30% mass fraction, and then stirred with magnetic force at 900 r/min for 15 minutes to obtain tungsten source solution.

3.15 g precipitator was added to the vanadium source solution: the precipitator was added to 75 mL vanadium source solution, and then the vanadium source solution was obtained by magnetic stirring at 900 r/min for 15 min.

4.Mix the vanadium solution with the tungsten solution: mix the vanadium solution with the tungsten solution, and get the mixed solution; then add the mixed solution to the polytetrafluoroethylene hydrothermal reactor, and seal the polytetrafluoroethylene hydrothermal reactor. Then the sealed polytetrafluoroethylene hydrothermal reactor was reacted for 48 hours at 80 ℃ and then naturally cooled to room temperature to obtain black precipitate.

5.Washing: The black precipitates were washed six times with deionized water and absolute ethanol respectively, and then dried at 50 ℃ for 12 h to obtain vanadium pentoxide/tungsten oxide co-deposited cubic crystals.

Vanadium pentoxide and tungsten oxide composites are synthesized by hydrothermal or solvothermal methods. Most of the composites are spherical in shape. However, vanadium-tungsten nano-cubic crystal particles can be easily obtained by this method, and the process requirements are loose, the preparation time is short and the yield is high.

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