A kind of preparation method and application of nano platinum oxide catalyst

Abstract

The invention discloses a preparation method and application of a nanometer platinum oxide catalyst. The preparation method comprises the following concrete steps: heating a platinum salt solution to about 65 DEG C; then rapidly adding an oleate solution (a mixed solution of oleic acid and excess sodium hydroxide) and carrying out rapid stirring for 10 to 15 min so as to obtain a mixed platinic hydroxide solution; adding cetyl trimethyl ammonium bromide and hydrogen peroxide with a concentration of 30% into the solution and stopping a reaction in 30 to 40 min so as to obtain a nanometer platinum oxide colloidal solution, wherein nanometer platinum oxide are uniformly dispersed in the solution due to existence of oleate and cetyl trimethyl ammonium bromide; and adding materials like AC100, RC25 and RC35 into the nanometer platinum oxide colloidal solution, then carrying out mixing and drying; and then carrying out sintering to 550 DEG C so as to prepare nanometer platinum oxide catalyst powder. According to the invention, the specific surface area of platinum oxide in the catalyst material is increased through preparation of nanometer platinum oxide, so the distribution rate and usage efficiency of platinum in the catalyst are improved; and thus, the purposes of thorough utilization and improvement of catalytic activity of platinum oxide are achieved.

Description

technical field [0001] The invention belongs to the field of catalysis, and in particular relates to a preparation method and application of a nanometer platinum oxide catalyst. Background technique [0002] Catalysts for automobile exhaust purification are divided into two types: oxidation catalysts and reduction-oxidation catalysts (three-way catalysts, Three-WayCatalyst). Oxidation catalysts were widely used in the 1970s, and three-way catalysts were widely used after entering the 1980s. By 1988, three-way catalysts had accounted for 80% to 90%. The oxidation catalyst uses platinum or platinum palladium as the active component, and the carrier is gamma-Al203 balls or gamma-Al203 added. Coated ceramic honeycomb body, whose function is to convert the harmful CO and HC in the exhaust gas into CO2 and water. The three-way catalyst uses platinum and rhodium as the active component, and the carrier is a ceramic honeycomb coated with γ-Al203. Its function is to simultaneously ...

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Problems solved by technology

In this method, platinum nitrate is first produced, and the latter is decomposed to release nitrogen oxides and oxygen to obtain platinum oxide. The platinum oxide produced by this method is not nano-scale, and the characteristics of many nano-materials cannot be reflected in the catalyst material.

[0005] The platinum oxide particles prepared by the traditional method are formed at high temperature during the sintering process, and the atoms between different platinum particles are easy to diffuse. Hundreds of nanometers to tens of microns, and may be sintered with other noble metal elements (such as rhodium) to form a larger alloy body, the catalytic activity of the noble metal alloy formed in this way is relatively weak. The relatively small surface area will inevitably cause the precious metal in the inner core of the particle to not be in direct contact with the exhaust gas components, reducing the effective and full utilization of precious metals and causing waste of precious metals in use

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