Aqueous phase reforming of sorbitol on Pt/Al2O3: Effect of metal loading and reaction conditions on H2 productivity

Abstract

The production of hydrogen by aqueous phase reforming (APR) of sorbitol was studied on Pt-based catalysts at 498 K and 29.3 bar. Four alumina-supported Pt catalysts (0.30, 0.57, 1.50 and 2.77 %wt Pt) were prepared. The influence of both the metallic content and the weight hourly space velocity (WHSV, h-1) on sorbitol conversion and hydrogen selectivity, yield and productivity was investigated. Sorbitol conversion and H2 yield increased with the amount of Pt while the H2 selectivity in the gas phase did not change significantly. The H2 productivity was measured on all the catalysts at different WHSV in order to determine the operating conditions required to optimize the production of hydrogen. The H2 productivity increased with the amount of Pt and went through a maximum as the space velocity was increased. The highest H2 productivity (22 mmol H2/h gcat) was achieved on Pt(2.77%)/Al2O3 at WHSV = 1.8 h-1. At a given space velocity, the H2 productivity did not depend on the sorbitol concentration in the feed.