Maximizing the synergistic effect between Pt0 and Ptδ+ in a confined Pt-based catalyst for durable hydrogen production

Abstract

Methanol is a suitable raw material for in situ hydrogen generation by steam reforming that enables the safe storage and transportation of hydrogen. Pt-based catalysts have been considered promising and effective for methanol steam reforming but suffer from deactivation by metal sintering. In this study, we developed an efficient K-modified Pt catalyst confined within silicate-1 zeolite with a high activity and unprecedented stability for methanol steam reforming. Owing to the confinement effect, the K-promoted Pt@S-1 catalyst remained stable for more than 50 h. The combination of TPSR-MS and DFT calculations revealed that the Pt-K@S-1 catalyst exhibited a synergistic effect between the Pt0 and Ptδ+ species. The cleavage of the O–H bond in CH3OH was activated over Pt0 sites to produce HCOOCH3, whereas Ptδ+ sites promoted the hydrolysis of HCOOCH3 to HCOOH and ultimately CO2 and H2, thus suppressing the formation of CO and boosting H2 production.