Barium sulfate groups that are sensitive to overreduction. With a low surface area, the contact time of the substrate with the catalyst is shorter and thus selectivity is achieved. Palladium on barium sulfate is also used as a catalyst in the Rosenmund reduction. As barium compounds emit a green light when burned, barium salts are often used in green pyrotechnic formulas, but the nitrate and chlorate salts are more common. Barium sulfate is commonly used as a component of "strobe" pyrotechnic compositions. As barium sulfate has high burning point and is insoluble in water, it is used as a coating material in
Barium is then reduced by carbon to barium sulfide: The water-soluble barium sulfide is the starting point for other compounds: reacting BaS with oxygen produces the sulfate, with nitric acid the nitrate, with carbon dioxide the carbonate, and so on. The nitrate can be thermally decomposed to yield the oxide. Barium metal is produced by reduction with aluminium at . The intermetallic compound BaAl is produced first: BaAl is an intermediate reacted with barium oxide to produce the metal. Note that not all barium is reduced. The remaining barium oxide reacts with the formed aluminium oxide: and the overall reaction is