Method of separating, gathering and measuring platinum, palladium and rhodium in automotive catalyst

Abstract

The invention discloses a method of separating, gathering and measuring platinum, palladium and rhodium in automotive catalyst. The method comprises the following steps: (1) the dissolution of a sample: weighting 0.5-1.5g of uniform catalyst sample with the grain size of 150 meshes or less to place in a polytetrafluoroethylene digestion tank, adding HCl and H2O2, closing the lid; placing the digestion tank in a constant temperature oven to dissolve the catalyst, withdrawing the digestion tank, transferring all the materials into a beaker by using distilled water, evaporating, filtrating, adding filtrate in a volumetric flask, performing constant volume, mixing evenly; (2) the coprecipitation, separation and enrichment of tellurium: pipetting a certain amount of sample solution into a beaker, adding concentrated hydrochloric acid and tellurium solution, controlling the solution to boil on an electric hot plate, dropwise adding SnCl2 solution to ensure that the yellow color disappears, alarge number of precipitate is prepared and some SnCl2 solution is excessive, heating continuously, replenishing tellurium solution, boiling the solution to boiling gently, taking the beaker down tocool the solution to room temperature, filtrating the solution, washing with water, precipitating; dropwise adding fresh warm aqua regia to dissolve, washing the funnel with water for several times; heating the solution to be nearly dry, transferring the obtained product with HCl to a volumetric flask, performing constant volume, mixing evenly; (3) measuring the content of Pt, Pd and Rh with ICP-AES under optimum instrument conditions.

Description

technical field [0001] The invention relates to an accurate and rapid determination method for platinum, palladium and rhodium in automobile catalysts, in particular to a method for accurately and rapidly determining platinum, palladium and rhodium, which can eliminate measurement interference after tellurium co-precipitation, separation and enrichment. Background technique [0002] With the rapid development of my country's automobile industry, the number of automobiles has increased rapidly, and the environmental pollution caused by carbon monoxide and nitrogen oxides in automobile exhaust has become increasingly serious. It has become an important factor of environmental pollution and has attracted the attention of the whole society. Controlling and treating tail gas pollution has become an important task at present. The installation of automobile exhaust purification catalyst is the main means to reduce exhaust pollution. [0003] Automobile exhaust gas purification cat...

AI Technical Summary

Problems solved by technology

The domestically established spectrophotometric method for the simultaneous determination of Pt and Pd with the dual-wavelength spectrophotometric method of dibenzyldithiooxalamide-potassium iodide-ascorbic acid and the determination of Rh with the extraction spectrophotometric method of 2-mercaptobenzothiazole-stannous bromide has been established. It is a relatively mature method. Since Pt, Pd, and Rh need to be extracted and separated separately during the determination process, the analysis speed is relatively slow. It usually takes 2 days to get the result after the sample is dissolved, which cannot meet the requirements of rapid determination.

Although the ICP-AES method has the advantages of low detection limit, high precision, wide linear range, and fast speed, there are also a large number of interference problems in the direct determination of Pt, Pd, and Rh in autocatalysts. Some related research work has been published, but it is still weak and lacks systematic work