Aqueous phase reforming of ethylene glycol over bimetallic platinum-cobalt on ceria-zirconia mixed oxide

The roles of cobalt promoter on the bimetallic platinum-cobalt supported on the CeO2-ZrO2 mixed oxide were investigated for aqueous phase reforming reaction of ethylene glycol (EG) to verify the effects of cobalt to an enhanced activity and stability of PtCo/CeO2-ZrO2, where the CeO2-ZrO2 mixed oxide was prepared by sol gel method at a fixed Ce/(Ce + Zr) molar ratio of 0.4. The enhanced catalytic activity for an aqueous-phase reforming (APR) as well as water gas shift (WGS) reaction of EG was observed on the PtCo/CeO2-ZrO2 at a Co/Pt molar ratio of 0.5. The higher activity and stability on the PtCo/CeO2-ZrO2 at an optimal Co/Pt ratio were mainly attributed to an enhanced WGS activity and less aggregation of active metals due to a high dispersion of platinum nanoparticles with a proper interaction between platinum and oxophilic cobalt nanoparticles. A facile reduction behavior of the supported bimetallic platinum-cobalt nanoparticles through an enhanced hydrogen spillover on the platinum nanoparticles also increased C-C cleavage reaction of EG with the suppressed deposition of inactive coke precursors on the partially reduced active nano particles. These synergy effects of platinum-cobalt nanoparticles with a close interaction and a less aggregation of active metals were responsible for an enhanced APR and WGS activity on the PtCo/CeO2-ZrO2 at an optimal Ce/(Ce + Zr) ratio as well. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.