Improvement of low temperature activity and stability of Ni catalysts with addition of Pt for hydrogen production via steam reforming of ethylene glycol

Hydrogen production by steam reforming of ethylene glycol (EG) at 300 degrees C was investigated over SiO2 and CeO2 supported Pt-Ni bimetallic catalysts prepared by incipient wetness impregnation methods. It was observed that impregnation sequence of Pt and Ni can affect the performance of catalysts apparently. Catalyst with Pt first and then Ni addition showed higher EG conversion and H-2 yield owing to the Ni enrichment on the surface and the proper interaction between Pt and Ni. It was observed that although SiO2 supported catalysts exhibited better activity and H-2 selectivity, CeO2 supported ones had better stability. This is attributed to the less coke formation on CeO2. Increasing Pt/Ni ratio enhanced the reaction activity, and Pt-3-Ni-7 catalysts with 3 wt% Pt and 7 wt% Ni showed the highest activity and stability. Ni surficial enrichment facilitated the C-C bond rupture and water gas shift reactions; and Pt addition inhibited methanation reaction. Electron transfer and hydrogen spillover from Pt to Ni suppressed carbon deposition. These combined effects lead to the excellent performance of Pt-3-Ni-7 supported catalysts. (C) 2019, Institute of Process Engineering, Chinese Academy of Sciences. Publishing services by Elsevier B.V.