Effect of CeO₂ addition to Al₂O₃ supports for Pt catalysts on the aqueous-phase reforming of glycerol.

A series of Pt catalysts supported on Al₂O₃ that was doped with different amounts of CeO₂ was developed, characterized, and tested in the aqueous-phase reforming (APR) of glycerol to H₂. Catalyst 3Pt/3CeAl, which bore 3 wt% Pt on a support that contained 3 wt % CeO₂, showed the highest carbon conversion to gas (85%) and the highest H₂ yield (80%) for a feedstock of 1 wt% glycerol in water at 240 °C and 40 bar. A CeO₂/Al₂O₃ support with only 1 wt% Pt also showed high H₂ selectivity and carbon conversion to gas, as well as a much lower CH₄ yield than the benchmark 3Pt/Al catalyst, clearly demonstrating that doping the support with 3 wt% CeO2 improved the APR of glycerol. H₂ chemisorption results showed that the highest metal dispersion (58%) and active surface area (4.3 m(2)g(-1)) were achieved for the support that contained 3 wt% CeO₂, and this effect appeared to be primarily responsible for the high H₂ yield and carbon conversion to gas. No CO was observed in the product gas; therefore, this gas could potentially be used directly in proton exchange membrane fuel cells. Thus, including CeO₂ in the Al₂O₃ catalyst support enhanced both the activity and selectivity towards H₂ of a Pt catalyst for the APR of glycerol.