Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6453545 | Applied Catalysis B: Environmental | 2018 | 11 Pages |
â¢Cu, Ni and Cu-Ni catalysts on ZSM-5 and Al2O3 evaluated on glycerol hydrogenolysis.â¢Under inert atmosphere only bimetallic catalysts showed formation of propylene glycol.â¢Glycerol reforming is the dominant reaction for Ni monometallic catalysts.â¢When H2 is added Cu monometallic catalysts presented higher propylene glycol yield.
A series of Cu, Ni and Cu-Ni catalysts with 20 wt% of each metal, supported on Al2O3 and ZSM-5, was prepared by wet impregnation method and tested in glycerol hydrogenolysis to 1,2-propanediol (propylene glycol) using a WHSV of 2 hâ1 at 250 °C, and pressure of 40 bar for 6 h. Without external hydrogen, the reaction pathway involves glycerol dehydration to acetol, with simultaneous reforming to H2 and CO2; this hydrogen generated in situ is used for the hydrogenation of acetol to propylene glycol. Under these conditions, the CuNi/Al2O3 and CuNi/ZSM-5 catalysts exhibited the highest glycerol conversion, 80% and 85%, respectively, with propylene glycol yield around 25%. With external hydrogen, all catalysts showed higher glycerol conversion (>90%) and the monometallic Cu catalysts presented higher conversion to liquid and propylene glycol yield than the bimetallic ones; the Cu/Al2O3 showed the highest yield to propylene glycol (70%). The activity of the catalysts was correlated with their metallic dispersion and also the support acidity.
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