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

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 H-2 yield increased with the amount of Pt while the H-2 selectivity in the gas phase did not change significantly. The H-2 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 H-2 productivity increased with the amount of Pt and went through a maximum as the space velocity was increased. The highest H-2 productivity (22 mmol H-2/h g(cat)) was achieved on Pt(2.77%)/Al2O3 at WHSV = 1.8 h(-1). At a given space velocity, the H-2 productivity did not depend on the sorbitol concentration in the feed. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.