Hydrogen production via aqueous-phase reforming of methanol over nickel modified Ce, Zr and La oxide supports

Aqueous-phase reforming (APR) of methanol over nickel supported on zirconium, cerium and lanthanum oxides was performed in continuous laboratory scale reactor and discussed in this paper. The role of composition and physico-chemical properties of the supports were investigated and significant benefit of using mixed oxides CeO₂-ZrO₂ and La₂O₃-ZrO₂ over the pure oxides, in term of methanol conversion and hydrogen production, was demonstrated. Methanol conversion of over 50% with hydrogen production efficiency of over 40% were achieved with the most active catalyst Ni/25%CeO₂-ZrO₂.Furthermore, catalyst stability, the most challenging issue within APR studies, was thoroughly investigated and discussed. Slight deactivation of the prepared catalysts during APR experiments or reduction was observed and addressed to the Ni particles sintering. On the other hand, other common reasons causing catalysts deactivation under APR conditions, such as leaching of Ni, changes in Ni oxidation state or changes in the supports lattice were not observed by wide range of characterization methods The most stable catalyst, Ni/10%La₂O₃-ZrO₂, exhibited a slight decrease of MeOH conversion within two subsequent experiments (each per 6h) from 46.3% to 42.7%.