摘要 |
<p>The present invention is for a process for making a heteropoly acid compound catalyst for oxidation of unsaturated aldehydes, such as methacrolein, to unsaturated carboxylic acids, such as methacrylic acid, said catalyst containing oxides of molybdenum, phosphorus, and M', wherein M' is cesium, potassium, rubidium, or sodium, and bismuth. The process is a synthesis of the catalyst with specific process conditions for addition of the bismuth compound as an aqueous slurry without nitric acid. A catalyst precursor is formed by removing the water and drying the solid particles. The heteropoly acid compound catalyst is formed by calcination of the catalyst precursor.</p> |