Stabilized *Oh Species by K+-Doped Pt for H2 Generation with Ultra-Low Levels of Co Through Aqueous-Phase Reforming of Methanol at Low Temperature

Abstract

Aqueous-phase reforming of methanol (APRM) is an attractive approach for H2 storage and transportation. However, the poor capability of water activation and weak stabilization of *OH intermediates on metals lead to the unsatisfactory activity and unavoidable CO generation at low temperatures. Herein, we demonstrated that K+ doped Pt nanoparticles on γ-Al2O3 (PtKx/Al2O3) generated the stabilized *OH intermediates on Pt surface, thereby achieving the efficient H2 generation with ultra-low levels of CO (＜10 ppm) through APRM process at 120 °C. Mechanism investigations illustrated that K+ in Pt shifted itsd-band center to stabilize the critical *OH from water dissociation and delivered no interference on methanol dissociation. Consequently, the PtKx/Al2O3 catalysts delivered a TOF of 142.3 h-1 and CO level below 10 ppm at 120 °C. These findings are anticipated to promote the delivery of hydrogen with high purity on mobile devices with methanol as a practical H2 carrier.

Keywords: H2 generation, ultra-low levels of CO, aqueous-phase reforming of methanol, low temperatures