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Why did platinum catalysts lose activity in early sulfuric acid manufacturing processes?
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catalysis
Nanoparticles of a gold-palladium (yellow-blue) alloy supported on acid-treated carbon (gray) directly catalyzing hydrogen peroxide formation from hydrogen (white) and oxygen (red) while shutting off unwanted hydrogen peroxide decomposition.
In early sulfuric acid manufacturing, the contact process initially utilized platinum as a catalyst to oxidize sulfur dioxide into sulfur trioxide. However, this process was frequently abandoned because the platinum catalyst would lose its activity over time.12
This loss of effectiveness was caused by catalyst poisons present in the reactants. These substances accumulate on the surface of the solid catalyst, blocking active sites and preventing the chemical reaction from proceeding efficiently. Once the presence of these poisons was identified and addressed, the contact process became a technical success at the turn of the 20th century. Eventually, platinum was replaced by vanadium catalysts, which are now standard in the industry.2314