H2 production from aqueous-phase reforming of glycerol over Cu-Ni bimetallic catalysts supported on carbon nanotubes

Aqueous-phase reforming of glycerol was investigated over a series of Ni and Cu-Ni bimetallic catalysts supported on multiwalled carbon nanotubes (MWNT). The reaction was carried out in a continuous flow fixed bed reactor (240 degrees C, 40 atm) with a solution of 1 wt% glycerol in DI water at a flow rate of 0.05 mL/min. Amongst the catalysts tested, bimetallic 1Cu-12Ni/MWNT catalyst gave the higher H-2 selectivity (86%) and glycerol conversion (84%) than the benchmark 12Ni/MWNT catalyst. Irrespective of Cu and Ni ratio, bimetallic Cu-Ni catalysts showed higher selectivity and glycerol conversion towards H-2 production than the Ni catalyst. The presence of Cu in bimetallic catalysts resulted in suppression of undesirable methanation reaction. Catalysts characterized by XRD and XPS showed a significant peak shift of Ni in bimetallic Cu-Ni catalysts than the Ni catalyst, suggesting a strong interaction between Cu and Ni. Also H-2-TPR analysis showed that introducing Cu increased Ni reducibility. The bimetallic interaction is thought to be responsible for the lowered methane yield and ultimately, higher hydrogen yield observed. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.