Preparation method of platinum nitrate

Abstract

The invention relates to the technical field of inorganic synthesis, and discloses a preparation method of platinum nitrate, which comprises the following steps of: (1) completely dissolving sponge platinum in a mixed solution of nitric acid and hydrochloric acid, concentrating, removing nitrate by using concentrated hydrochloric acid, and separating a product to obtain a chloroplatinic acid solid; (2) heating and decomposing the chloroplatinic acid solid to obtain a platinous chloride solid; (3) dissolving the platinous chloride solid in hydrochloric acid to obtain a chloroplatinous acid solution; (4) adding a sodium hydroxide solution into the chloroplatinous acid solution for precipitation reaction, separating out a precipitation reaction product, and washing the precipitation reaction product to remove chloride ions to obtain a platinum-containing precipitate; and (5) mixing the platinum-containing precipitate with concentrated nitric acid, reacting, and separating a product to obtain platinum nitrate. According to the method, chloroplatinic acid is converted into chloroplatinous acid by adopting a mode of firstly decomposing at high temperature and then dissolving with hydrochloric acid, so that the yield of platinum nitrate can be improved.

Description

technical field [0001] The invention relates to the technical field of inorganic synthesis, in particular to a preparation method of platinum nitrate. Background technique [0002] Platinum nitrate is an important compound of the noble metal platinum. As a precursor, it is widely used in the preparation of various platinum-containing catalysts, the synthesis of other platinum compounds, and the electroplating industry. At present, there are only a small amount of literature reports on the preparation method of platinum nitrate. The existing preparation methods mainly include sodium nitrite reduction method, molten salt ultrasonic synergistic method, hydroxyplatinum precipitation method, etc. These methods have disadvantages such as expensive reagents, high impurity content in the product, and the need to add stabilizers to the product solution. [0003] Patent US3666412 discloses a method for preparing platinum nitrate, mainly dissolving platinum dichloride in nitric acid s...

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Problems solved by technology

The existing preparation methods mainly include sodium nitrite reduction method, molten salt ultrasonic synergy method, hydroxyplatinum precipitation method, etc. These methods have disadvantages such as expensive reagents, high impurity content in the product, and the need to add stabilizers to the product solution.

[0003] Patent US3666412 discloses a method for preparing platinum nitrate, mainly dissolving platinum dichloride in nitric acid solution, and obtaining platinum nitrate by continuously catching up with hydrochloric acid, but because the binding ability of chloride ion and platinum is stronger than that of nitrate ions and nitrate ions are easier to decompose and volatilize than chloride ions, resulting in more residual chloride ions in platinum nitrate, which seriously affects the quality of platinum nitrate products

[0004] Patent CN104310498B discloses a preparation method of platinum nitrate, which uses sponge platinum to react with aqua regia, and makes chloroplatinic acid after nitrate removal, which can reduce the residual chloride ions, but the patent subsequently uses oxalic acid to reduce chloroplatinic acid After forming chloroplatinous acid, it is precipitated and dissolved to produce platinum nitrate, which has the problem of low yield