34results about How to "Does not destroy the crystal structure" patented technology

The invention discloses a method for preparing high-photo catalytic active nanometer titania by using waste wool. The method comprises the following steps: hydrolyzing wool under an acidity condition to generate amino acid small molecular substances, and performing doping modification on nanometer titania crystalline grains produced in the hydrothermal reaction process, covering a layer of organic substance film on the surface of the crystalline grains to prepare the nanometer titania with high-photo catalytic performance. Through the adoption of the hydrothermal method, the wool short fiber is added in the low-temperature hydrothermal and strong-acidity environment, in the growing process of the nanometer titania crystals, the wool fiber is synchronously hydrolyzed to generate the small molecular organic substances, thereby hybridizing the nanometer titania crystalline grains and performing the surface graft modification without adding other chemical reagents or surfactants; the preparation process is simple, the solution is neutral finally, and the emission cannot cause secondary pollution to the environment.

The invention discloses a small-grain Y type molecular sieve and a preparation method thereof. The small-grain Y type molecular sieve has the following properties: the mol ratio of SiO2 / A12O3 is more than 10 and less than 40; average grain diameter is 200 to 700 nm; relative crystallinity is above 100%; lattice constant is 2.430 to 2.450 nm; specific surface area is 850 to 1000 m2 / g; pore volume is 0.50 to 0.80 mL / g; the pore volume of secondary pores with a diameter of 1.7 to 10 nm is more than 50% of the total pore volume; and Na2O content is no more than 0.15 wt%. According to the preparation method, an NaY molecular sieve with a high Si / Al ratio, high crystallinity and good stability is used as a raw material, and caustic washing, ammonium exchange, hydrothermal treatment and treatment with a mixed solution of acid and ammonium salt are successively carried out so as to obtain the small-grain Y type molecular sieve. The small-grain Y type molecular sieve prepared in the invention is applicable as a cracking component of a light oil type hydrocracking catalyst and enables the catalyst to have good activity, heavy naphtha selectivity and excellent product nature.

The invention discloses a method for modifying small-grain NaY molecular sieves. In this method, the NaY type molecular sieve raw material with high silicon-aluminum ratio, high crystallinity and good stability is sequentially subjected to alkali washing, ammonium exchange, dealumination of silicon, hydrothermal treatment and treatment with a mixed solution of acid and ammonium salt to obtain The small-grain Y-type molecular sieves obtained higher SiO 2 / A1 2 o 3 At the same time, the proportion of secondary pores is high, and the stability of Y-type molecular sieve is maintained. The molecular sieve has a high specific surface area and high crystallinity. The Y-type molecular sieve obtained by the invention is suitable as a cracking component of a hydrocracking catalyst for high-medium oil, and can make the catalyst have good activity, medium-oil selectivity and excellent product properties.