Chromium trioxide is an inorganic compound with the chemical formula Cr₂O₃, also known as chromium(III) oxide or chromium green. It is a green solid with a variety of crystal structures, the most stable of which is α-Cr₂O₃, which belongs to the corundum structure. Chromium trioxide has a high melting point (about 2260 °C) and is a substance that is poorly soluble in water, but can be soluble in strong acids to form chromium salts.

Uses of Chromium Trioxide

1. Pigment: Chromium trioxide is a high-temperature, corrosion-resistant green pigment used in products such as ceramics, glass, paints, plastics, and printing inks.

2. Refractories: Due to its high melting point and good heat resistance, chromium trioxide is used as a component of refractory materials in the manufacture of furnace linings, kilns, and other structural materials in high-temperature environments.

3. Catalyst: In chemical reactions, chromium trioxide can be used as a catalyst to promote oxidation, reduction and acid-base reactions. It is commonly used in the production of petrochemicals, synthetic rubber, and synthetic resins.

4. Ceramic and glass industry: Chromium trioxide is used in the manufacture of ceramic and glass products, not only as a pigment, but also because of its chemical stability and high temperature resistance, it is used to improve the wear and corrosion resistance of products.

5. Metal refining and alloy manufacturing: In the metallurgical industry, chromium trioxide is used to refine metallic chromium and make alloys, such as stainless steel.

6. Electronics industry: Due to its electrochemical properties, chromium trioxide can be used as a cathode material for lithium-ion batteries to improve the energy density and thermal stability of the battery.

7. Magnetic materials: Chromium trioxide is mixed with other metal oxides and can be used to make magnetic materials, such as magnetic heads used to store data.

8. Trap: In the chemical industry, chromium trioxide can be used as a trap for adsorption and removal of harmful substances such as sulfur compounds and nitrogen oxides from gases.

9. Research and teaching: In scientific research and higher education, chromium trioxide, as a representative compound of chromium, is used in research and teaching in chemistry, physics, and materials science.