Fundamental understanding of the role of K on the activity of Pt/CeO₂ catalyst for hydrogen production from ethanol and ethylene glycol

Biomass has been proposed as a feedstock for fuels and chemicals in response to the imminent depletion of fossil fuels and the increasing concern on environmental protection. Hydrogen production for use in fuel cells, which has emerged as one of the most important technologies for meeting future global energy needs, can be achieved by the reforming of light oxygenated hydrocarbons, such as methanol, ethanol, and ethylene glycol (EG). In this symposium, the effect of potassium on the activity of Pt/CeO₂ catalyst for hydrogen production from EG will be presented. We have synthesized two series of Pt-K/CeO₂ catalysts to understand the influence of potassium to the physical and chemical properties of Pt/CeO₂ catalysts. The physical and structural properties of the catalysts were characterized with synchrotron-based X-ray diffraction (XRD), CO pulse chemisorption, temperature programmed reduction (TPR), and the activity property was probed with EG-temperature programmed desorption (TPD) experiments. The physical property results showed that The addition of potassium, regardless of the addition sequence, affects the dispersion of surface Pt species and the amount of bulk Pt species on CeO₂; The interaction between Pt and CeO₂ in the samples follows the sequence as K-Pt/CeO₂> Pt/CeO₂> Pt-K/CeO₂. The activity results demonstrated that Better activation ability to C-H or O-H bonds was observed in K-Pt/CeO₂, thus leading to higher activity for H₂ production at a lower temperature; Better activation ability to C-C bonds was showed in Pt-K/CeO₂, resulting in higher activity at a higher temperature. This work provides us insight to develop novel catalytic materials for hydrogen production from biomass resources.