The Preparation Of Nanometer Titanium Dioxide Used For Denitration Catalyst Supportor With Uniform Particle Size

The core of selective catalytic reduction(SCR) denitration is the catalyst, one important component of the catalyst is the carrier. The stand or fall of carrier determines the mechanical strength and the specific surface area of catalyst. The carrier to load active component needs to have large specific surface area, so we can make the catalyst has good performance. Nano Ti O2 with anatase type has smaller particle size, large specific surface area and strong adsorption ability of nature, thus it is good for loading active component and widely usd in the denitration technology. At present, most of the tenitration catalysts used in industry have been based on nano Ti O2 of anatase type as the carrier. But the particle size of commercial nano titanium dioxide distributes unevenly, size distribution range is broader and particle size is also commonly larger. The particle size of nano titanium dioxide used as photocatalyst is too small, usually 1-10 nm. The raw materials used in the preparation of that type of nano titanium dioxide cost highly, and the preparation technology is also not suitable for industrial production. The titanium dioxide whose particle size distributes uniformly and is 20-40 nm has a larger specific surface area and strong surface acidity etc, so it can meet the requirements of the industry catalyst.The sol-gel method of titanium dioxide has been studied very much. But these studies are mainly for nano titanium dioxide used as photocatalyst and the particle size of nano Ti O2is1-10 nm. That type of nano titanium dioxide used fou SCR denitration catalyst is too small.In this paper, according to the current research status, we aimed at preparaing the titanium dioxide that was suitable for industrial catalyst carrier. In chapter ii of this article, we synthesized 20-40 nm nanometer titanium dioxide with uniform particle size respectively by sol-gel and homogeneous precipitation. In chapter ii of this article, nano-titania was synthesized by the sol-gel method, using titanium tetrabutoxide as the precursor and anhydrous ethanol as solvent. We explored that when the butyl titanate was 10 m L, solvent dosage was 69-80 m L, acetic acid dosage was 4-6 m L, the dosage of the water was 2-8 m L,and p H value was 2-3, the particle size of titanium dioxide was 20 ~ 40 nm. Then we synthesized nanometer titanium dioxide anatase type crystal structure under 600 ℃calcination. In chapter iii of this article, we synthesized nano-titania by the homogeneous precipitation method using titanyl sulfate as titanium source and the urea as precipitant. We studied that the conditions to prepare 20-40 nm nonometer Ti O2 were the ratio of oxygen titanium sulfate and urea was 1/2-1/4, reaction temperature was 86-90℃, reaction time was 4hours, calcination temperature was 600℃, and dosage of dispersants was 0.5-1 m L.