Efficient Hydrogen Production from Ethylene Glycol Steam Reforming Catalyzed by Na-Promoted Pt/γ-Mo2N

Abstract

Ethylene glycol (EG) derived from biomass and plastic wastes can serve as a sustainable H₂ resource through steam reforming (HOCH₂CH₂OH + 2H₂O ⇄ 5H₂ + 2CO₂). However, achieving high activity in H₂ production with good selectivity toward CO₂ under mild conditions poses a challenge. A thoughtful understanding of the active sites that accelerate the cleavage of the C–C bond rather than the C–O bond and the activation of the water molecule is still lacking. In this study, we developed a PtNa/γ-Mo₂N catalyst that efficiently enables hydrogen production from ethylene glycol steam reforming (EGSR) reactions. This catalyst achieved outstanding H₂ productivity, reaching 6000 mol_H2·mol_Pt^–1·h^–1 at 250 °C under 10 bar with high CO₂ selectivity (89%) and low CO selectivity (1%) in carbon-containing products. Comprehensive characterizations revealed the crucial role of the interface between highly dispersed Pt species and Mo₂N in activating ethylene glycol and water. Additionally, sodium (Na) was found to block acidic sites, preventing the formation of side products from C–O bond cleavage, and to modulate Pt sites, enhancing the reforming process by accelerating the water gas shift reaction.