Efficient Hydrogen Production from the Aqueous-Phase Reforming of Biomass-Derived Oxygenated Hydrocarbons over an Ultrafine Pt Nanocatalyst

Abstract

Hydrogen from biomass, as a promising alternative fuel, is becoming considerably attractive due to its high energy density and clean emissions. The aqueous phase reforming (APR) of biomass-derived oxygenated hydrocarbons and water is a renewable and efficient pathway for hydrogen production and shows great potential. However, the key to the application of this technique is to develop catalysts with high hydrogen productivity. In this work, we first synthesized polyaniline–platinum (PANI-Pt) organo-metallic hybrid precursors and then obtained a high-loaded (~32 wt.% Pt) and highly dispersed (~3 nm Pt particles) Pt@NC−400 catalyst after pyrolysis at 400 °C, and the nanoparticles were embedded in a nitrogen-doped carbon (NC) support. The Pt@NC−400 catalyst showed an almost three times higher hydrogen production rate (1013.4 μmolH2/gcat./s) than the commercial 20% Pt/C catalyst (357.3 μmolH2/gcat./s) for catalyzing methanol–water reforming at 210 °C. The hydrogen production rate of 1,2-propanediol APR even reached 1766.5 μmolH2/gcat./s over the Pt@NC−400 catalyst at 210 °C. In addition, Pt@NC−400 also exhibited better hydrothermal stability than 20% Pt/C. A series of characterizations, including ICP, XRD, TEM, SEM, XPS, N2 physisorption, and CO chemisorption, were conducted to explore the physiochemical properties of these catalysts and found that Pt@NC−400, although with higher loading than 20% Pt/C (~23 wt.% Pt, ~4.5 nm Pt particle), possessed a smaller particle size, a more uniform particle distribution, a better pore structure, and more Pt metal active sites. This study provides a strategy for preparing high-loaded and highly dispersed nanoparticle catalysts with high hydrogen productivity and sheds light on the design of stable and efficient APR catalysts.

Keywords

• oxygenated hydrocarbons
• Pt@NC catalysts
• aqueous phase reforming
• hydrogen production