Role of Sn in Ni-Sn/CeO2 Catalysts for Ethanol Steam Reforming

Reducible oxides （e.g.,CeO2 and ZrO2） supported 3d transition metals （e.g.,Ni,Co,Pt） exhibit remarkable catalytic activity in reactions that involve water activation,such as steam reforming and water gas shift.This paper describes the influence of Sn addition on the performance of Ni/CeO2 catalysts in ethanol steam reforming.0.25 wt% Sn addition improved the stability of Ni/CeO2 by forming Ni-Sn bimetallic nanoparticles with Sn enriched surfaces to suppress the carbon deposition.Ni0.25Sn/CeO2 kept over 90% ethanol conversion in a 20 h stability test at 600 ℃ with over 60% hydrogen selectivity under a gas hourly space velocity of 57000 mL/（g·h）.However,the presence of Sn decreased the overall oxygen storage capacity and oxygen mobility of NiSn/CeO2,which hampered water activation process and coke elimination occurring at the interface between Ni and CeO2.Additionally,ethanol decomposition was also suppressed due to the coverage of Sn atoms on Ni surfaces.