CeO2-supported Ni and Co catalysts prepared by a solution combustion method for H2 production from glycerol: the effect of fuel/oxidizer ratio and oxygen excess

Abstract

Glycerol is a promising raw material for obtaining various chemicals and fuels, including H₂. Nevertheless, the development of cost-effective and stable catalysts with high activity and selectivity for H₂ production from glycerol under mild conditions has been a serious problem for their practical use. In this work, a series of CeO₂-supported Ni and Co catalysts with the content of Ni and Co as metal(II) oxides being 30 wt% was prepared by solution combustion synthesis via changing the fuel/oxidizer ratio (φ = 0.7–3), the fuel type (glycine, urea), and the oxygen excess. Thus, various species of Ni and Co and their interactions with CeO₂ were obtained, which affected the reduction sequence, defectiveness, textural characteristics, and activity in steam and aqueous-phase reforming of glycerol. To study the characteristics of the obtained samples, instrumental methods such as XRD, DTA-TGA, low-temperature N₂ physisorption, SEM-EDX, H₂-TPR, and H₂- and CO₂-TPD, as well as Raman spectroscopy, were used. The results demonstrated that the Ni–Ce–O system synthesized with a high glycine-to-oxidizer ratio can successfully compete with catalysts based on noble metals (Pt/γ-Al₂O₃) in aqueous-phase reforming of glycerol.