Selective Oxidation of 1,3-Butanediol to 3-Hydroxybutyric Acid over PtSb2 Alloy

3-Hydroxybutyric acid (3-HBA) is an important monomer for manufacturing biodegradable polymers such as polyhydroxyalkanoates, which are currently produced via an expensive and time-consuming microbial fermentation route. Herein, the catalytic synthesis of 3-HBA via the selective oxidation of 1,3-butanediol (1,3-BDO) in the presence of molecular oxygen is reported for the first time. It was found that the PtSb2 alloy could catalyze the selective formation of 3-HBA, and the selectivity of 3-HBA was 82.3% at a 1,3-BDO conversion level of 95.5%. The calculated turnover frequency of each surface Pt atom in the PtSb2/AC catalyst was 344.3 h–1 at 70 °C. The characterization results indicated that the prominent performance of the PtSb2 alloy over monometallic Pt nanoparticles could be because the alloy could promote the tandem oxidation of the 3-hydroxybutyraldehyde (3-HBAD) intermediate to 3-HBA and reduce the dehydration of 3-HBAD to the byproduct. At the same time, the PtSb2 alloy was also effective for the selective oxidation of several diols to hydroxyl-substituted acids.