Base-Free Direct Oxidation of 1-Octanol to Octanoic Acid and its Octyl Ester over Supported Gold Catalysts

The choice of a suitable support for gold nanoparticles (Au NPs) enabled the direct oxidation of unreactive aliphatic alcohol, 1-octanol, to octanoic acid and octyl octanoate in the absence of a base. Under optimized conditions, Au NPs supported on NiO (Au/NiO) exhibited remarkably high catalytic activities and excellent selectivities to octanoic acid (e.g., 97%) at full conversion. In contrast to Au/NiO, Au/CeO2 selectively produced octyl octanoate as a major product in a base-free aqueous solution with a maximum selectivity of 82% under optimized conditions.