Hydrogen production on Pd0.01Zn0.29Mg0.7Al2O4 spinel catalyst by low temperature ethanol steam reforming reaction

Abstract

This study investigated the low-temperature ethanol steam reforming (LTESR) performance of a Pd0.01Zn0.29Mg0.7Al2O4 catalyst. Although it was present in a very small amount, the Pd component was the key to the partial CO-water gas shift and CO-methanation that, eventually, helped to increase the yield of H2 during LTESR. An 80% yield of H2 was maintained even after 30 h at 450 °C on the Pd0.01Zn0.29Mg0.7Al2O4 catalyst with 100% ethanol conversion. Furthermore, the spinel structure of the catalyst remained unchanged after the reaction, and there was no increase in size owing to particle-to-particle aggregation. This study demonstrated that the Pd and Zn components could be stably located in the spinel structure of the MgAl2O4 with no sintering of the particles. Moreover, the oxygen transfer capacity of the MgAl2O4 spinel structure helped maintain the catalytic performance for long time periods by transferring oxygen to the reduced catalytic metal species (Zn or Pd) during the reaction, even though this induced oxygen defects in the spinel crystal. Overall, improved catalyst activity and an extended catalyst lifespan were observed.