Platinum-group metals have the advantages of excellent catalytic activity, high selectivity, long service life and recyclable regeneration. Their research and development are of great significance to industrial and social development.
Chemical and petrochemical catalysts. More than 80% of chemical reactions are related to catalysis, among which platinum group metal catalysts play an important role. For example, platinum rhodium for ammonia oxidation in the nitric acid industry, or platinum palladium rhodium catalytic network, has been the core of the nitric acid industry for 70 years. In recent years, some fine chemical and precious metal catalysts use carrier catalysts and develop towards homogeneous multifunctional catalysts. In order to improve the octane number of automobile oil, petroleum reforming has been inseparable from platinum, platinum, platinum and other base catalysts. In addition, cracking, hydrogen and other catalysts are mostly based on platinum or palladium.
Catalysts for carbonization and carbonization refer to the preparation of various chemical products and emerging industrial fields from coal and gas, i.e., materials containing one carbon atom in molecules such as methane, carbon monoxide and methanol. The most promising in this field are platinum group metal complexes or metal compounds catalysts.
Catalysts used for waste gas purification are mainly used for the treatment of automobile exhaust. Carbon monoxide, hydrocarbons and nitrogen oxides in the exhaust gas can be eliminated simultaneously by using oxygen sensor and electronic computer air-fuel ratio feedback control system. At the same time, the content of platinum-group metals in the catalyst was determined.
Some precious metals with less than 1m particles have conductivity and optical activity. , low temperature magnetization rate, specific heat, nuclear magnetic relaxation and other aspects of the abnormal phenomenon of energy level discontinuity, and surface activity increased, the ignition point decreased. It can be used in catalyst, sensor, low temperature sintering, conductive slurry, solar energy absorbing film, dilution frozen insulation material, etc.
Metallized metal fibers and metal powders are mixed into polymer materials, such as rubber, to make anisotropic conductive rubber for use in light-emitting diodes, liquid crystal components, and mixed integrated electricity. Polyacetylene and graphite interlayer compounds can be conductive by using platinum group metal compounds.
The precious metal amorphous alloys studied at present include platinum, gold, palladium, rhodium and iridium alloys. The main USES are catalyst, magnetic motor material, electrode material, hydrogen storage material, high strength material, solder material, etc.
The anti-corrosion ability of titanium was greatly improved by adding 0.2% palladium to titanium. Add 0.1-3% platinum to stainless steel to reduce the corrosion rate of stainless steel to 1/10. Other recently proposed corrosion resistant alloys are: ti-ru-w (mO or Ni) alloys.
The surface of stainless steel has 0.003 m passivated film, so the conductivity is poor and cannot be brazed, which limits the application in the electronic industry. However, as long as the surface of stainless steel is plated with 0.1-0.5m thick gold, there will be conductivity and brazing property, thus opening up the application in the electronics industry.
Precious metals are widely used and play an important role in the development of new and high technology. With the development of science and technology, its application fields and USES will expand and play an increasingly important role.
