Catalytic dehydroxylation of glycerol to propylene glycol over Cu–ZnO/Al₂O₃ catalysts: Effects of catalyst preparation and deactivation

• Published in: Catalysis today Vol. 174; no. 1; pp. 59 - 64
• Main Authors: Panyad, Suchart, Jongpatiwut, Siriporn, Sreethawong, Thammanoon, Rirksomboon, Thirasak, Osuwan, Somchai
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 02.10.2011; Elsevier
• Subjects: carbon; Catalysis; catalysts; catalytic activity; Chemistry; Colloidal gels. Colloidal sols; Colloidal state and disperse state; Exact sciences and technology; General and physical chemistry; glycerol; hydrogen; leaching; metals; propylene glycol; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Propylene glycol; Binary compound; Hydrogen; Coke; Selectivity; O; Dehydroxylation; Precipitation; Copper; Co-precipitation; Aluminium oxide; Catalytic reaction; Deactivation; Sol-gel; Transition element compounds; Fixed bed reactor; Incipient wetness impregnation; Glycerol; Transition metal; Cu-ZnO/Al; Carbon; X ray diffraction; Heterogeneous catalysis; Impregnation; Propene; Sol gel process; Atmosphere; Sintering; Preparation; Alumina; Catalyst; Glycol
• ISSN: 0920-5861; 1873-4308
• DOI: 10.1016/j.cattod.2011.03.029

The dehydroxylation of glycerol to propylene glycol was investigated over Cu–ZnO/Al₂O₃ catalysts prepared by three different methods—incipient wetness impregnation (IWI), co-precipitation (COP), and sol–gel (SG). The prepared catalysts were tested for their catalytic activity and selectivity in a continuous flow fixed-bed reactor at 523K and 3.2MPa under hydrogen atmosphere. The fresh and spent catalysts were characterized by several techniques, including BET, XRF, XRD, TPR, and TPO. Among the catalysts tested, the Cu–ZnO/Al₂O₃ catalyst prepared by the IWI method provided the highest catalytic performance, which could be due to its low coke formation. XRD, TPR, and TPO results indicated that possible causes of the catalyst deactivation are the combination of carbon deposit and sintering of active metals. Copper leaching was also found in the catalyst prepared by SG method.