One-step, environmentally friendly process for the synthesis of solid oxide catalysts. The conventional production of catalysts requires acid-base precipitation with a metal nitrate, producing large volumes of nitrate and halogenated waste and emitting NOx and SOx gases. The extraction of nitrate and other salts generates large volumes of wastewater. This novel synthetic process eliminates aqueous and nitrate waste by using an organic acid, a pure metal, and an oxidizing agent that is usually air. The widely available metal reacts with the oxidizing agent under a moderate acidic reaction medium, generating the oxide species one step at ambient temperature. The elimination of nitrate waste reduces NOx emissions to nearly zero. The process also requires less water and energy input, producing only aqueous vapor and small volumes of carbon dioxide as byproducts. This process is estimated to avoid the generation of 29 million and 760 million pounds of nitrate and aqueous waste, respectively.
EPA Presidential Green Chemistry Challenge: 2003 Greener Synthetic Pathways Award
