Takao Maki

Novel direct hydrogenation process of aromatic carboxylic acids to the corresponding aldehydes with zirconia catalyst

Abstract A novel process for synthesizing aromatic aldehydes by a direct hydrogenation reaction of the corresponding carboxylic acids was established. The catalyst, modified zirconia, showed satisfactory performance for commercial production. The optimization of the catalyst, application to various carboxylic acids, and mechanistic considerations using reaction kinetics and FT-IR spectroscopy are reported.

An infrared study of selective hydrogenation of carboxylic acids to corresponding aldehydes over a ZrO2 catalyst: pivalic acid to 2,2-dimethylpropanal

A selective hydrogenation of pivalic acid ((CH3)3C-COOH) to 2,2-dimethylpropanal ((CH3)3C-CHO) was studied by infrared spectroscopy. While pivalic acid adsorbed on Cr2O3-ZrO2 as a carboxylate ((CH3)3C-COC−) above 303 K and decomposed at 773 K, it was reduced by H2 at 623 K. The adsorbed aldehyde changed into the carboxylic acid ion species above 523 K via several intermediate species observed below 303 K.

1.5 Novel Direct Hydrogenation Process of Aromatic Carboxylic Acids to the Corresponding Aldehydes with Zirconia Catalyst

A novel process for producing aromatic aldehydes by a direct hydrogenation reaction of the corresponding carboxylic acids was established. The catalyst, modified zirconia, showed excellent performance for commercial production. The catalyst screening, application to various carboxylic acid hydrogenation, and reaction mechanism are reported.