Bimetallic AuCu nanoparticles supported on CeO2 as selective catalysts for glycerol conversion to lactic acid in aqueous basic medium

• Published in: Journal of nanoparticle research : an interdisciplinary forum for nanoscale science and technology Vol. 21; no. 7; pp. 1 - 13
• Main Authors: Palacio, Ruben, López, Diana, Hernández, Diana
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-07-2019; Springer Nature B.V
• Subjects: Acids; Aqueous solutions; Basic converters; Bimetals; Catalysts; Catalytic converters; Cerium oxides; Characterization and Evaluation of Materials; Chemistry and Materials Science; Conversion; Copper; Copper converters; Glycerol; Gold; High temperature; Inorganic Chemistry; Lactic acid; Lasers; Materials Science; Nanoparticles; Nanotechnology; Optical Devices; Optics; Photonics; Physical Chemistry; Recyclability; Research Paper; Selectivity; Sodium hydroxide; Glycerol; Nanostructured catalyst; Gold catalyst; Biomass; Lactic acid; Bimetallic gold-copper
• ISSN: 1388-0764; 1572-896X
• DOI: 10.1007/s11051-019-4594-2

Gold-based catalysts, monometallic Au/CeO
2
or bimetallic AuCu/CeO
2
, evaluated on the glycerol conversion to lactic acid, demonstrated to be active and selective at a reaction temperature of 220 °C in aqueous basic medium at low base concentration. The concentration of NaOH slightly modified the activity of AuCu/CeO
2
for converting glycerol, while selectivity toward lactic acid increased on AuCu/CeO
2
catalyst but had no influence on Au/CeO
2
catalytic performance. Recyclability tests demonstrated that AuCu/CeO
2
kept high conversion for up to the fourth catalytic cycle and selectivity remained stable, while conversion on Au/CeO
2
significantly decreased in the second cycle. For instance, copper stabilized gold on AuCu/CeO
2
catalysts for converting glycerol to lactic acid in aqueous medium at relatively high temperature of 220 °C. Characterization of AuCu/CeO
2
catalyst using H
2
-TPR showed that the presence of Au modified the reduction events of Cu species, while HRTEM analysis of nanoparticles showed particles of an average size of 6.3 nm and lattice fringes for metallic Au and Cu. These results suggest that Au and Cu might be in close proximity.
Graphical abstract