Designation of highly efficient catalysts for one pot conversion of glycerol to lactic acid

• Published in: Scientific reports Vol. 6; no. 1; p. 29840
• Main Authors: Tao, Meilin, Dan Zhang, Guan, Hongyu, Huang, Guohui, Wang, Xiaohong
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 19.07.2016; Nature Publishing Group
• Subjects: 140/146; 142/136; 704/106; 704/158; Acid production; Acids; Catalysis; Glycerol; Humanities and Social Sciences; Metals; multidisciplinary; Oxidation; Oxidizing agents; Raw materials; Science
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/srep29840

Production of lactic acid from glycerol is a cascade catalytic procedure using multifunctional catalysts combined with oxidative and acidic catalytic sites. Therefore, a series of silver-exchanged phosphomolybdic acid catalysts (Ag x H 3−x PMo 12 O 40 , x = 1 ~ 3, abbreviated as Ag x PMo) was designed and applied in glycerol oxidation with O 2 as an oxidant to produce lactic acid (LA) without adding any base. Among all, total silver exchanged phosphomolybdic acid (Ag 3 PMo) was found to be the most active one with LA selectivity of 93% at 99% conversion under mild conditions of 5 h at 60 °C. The exceptionally high efficiency was contributed to the generation of strong Lewis acid sites, enhanced redox potentials and water-tolerance. More importantly, Ag 3 PMo was tolerant in crude glycerol from biodiesel production. And the reaction mechanism was also discussed. Meanwhile, Ag 3 PMo acted as a heterogeneous catalyst for 12 recycles without loss of activity.