Method for preparing large surface improved aluminium oxide with high temperature resistant performance

Abstract

The invention relates to a method of utilizing co-precipitation method to prepare modified alumina. Firstly, M-source materials and soluble aluminium salts are accurately weighed according to stoichiometric ratio needed by M-Al2O3, then M-source materials and soluble aluminum are dissolved in water, surface active agent is then added into the water with M-source materials and soluble aluminum, the mixed liquid is mixed and then precipitated with the solution of ammonium carbonate with dispersants under the temperature of 40 to 80 DEG C, pH(potential of Hydrogen) value is finally adjusted to 7 to 11, the mixed liquid is then vigorously stirred for 3 to 24 hours, filtered, washed, dried under the temperature of 100 to 120 DEG C, roasted for 4 to 6 hours under the temperature of 500 to 550 DEG C, and is reroasted for 2 to 6 hours under the temperature of 1100 to 1250 DEG C, and finally the produce is prepared. The invention has the advantages of low cost of raw materials, low temperature for synthesizing, simple operation, no pollution, good repeatability and easiness for large scale preparation, thereby being capable of promoting large scale commercial production of the modified alumina. Consequently, the invention can be pushed to be applied in reaction fields such as purifying exhaust gas of automobiles, methane partial oxidation to syngas, catalytic decomposition of propellant used in spacecraft and the like.

Description

field of invention [0001] The invention relates to the preparation of modified alumina, in particular to a method for preparing modified alumina with high temperature resistance and large specific surface, which still has a large specific surface area after high-temperature roasting. Background technique [0002] For the reaction fields such as automobile exhaust purification, methane partial oxidation to synthesis gas, etc., the reaction requires very high temperature, and alumina is one of the commonly used high-temperature resistant catalyst supports, but alumina is easy to sinter and transform to α phase above 1000 °C , leading to a sharp decrease in its specific surface area and clogging of micropores, resulting in the aggregation of active components on the load, reducing the activity of the catalyst and shortening its service life. At the same time, the reduction of the pore volume of the carrier is also not conducive to the mass transfer and heat transfer of the reac...

AI Technical Summary

Problems solved by technology

Using water-soluble organic silane polymer as the silicon source, and the impregnation method of finished alumina as the aluminum source to obtain modified alumina with high specific surface area, because the silane polymer is easily cracked during the roasting process to produce toxic organic substances, thereby polluting the environment. Not conducive to industrial production

Therefore, the modified alumina with high specific surface area prepared by the existing technology has the disadvantages of high raw material cost, complicated preparation process, and easy pollution of the environment, thus limiting the industrialization of the preparation of modified alumina.