Sulfur-tolerant Pt/Gd₂O₃-CeO₂-Al₂O₃ catalyst for high efficiency H₂ production from autothermal reforming of retail gasoline

Pt/CeO₂-Al₂O₃ catalysts with and without Gd₂O₃ additive were prepared by stepwise incipient wetness impregnation (IWI) method. The catalysts were tested for autothermal reforming (ATR) of retail gasoline containing 158-500 ppm sulfur under the optimal reaction conditions: 800 °C, gasoline WHSV of 0.9 h^-1 and a H₂O/O₂/C molar ratio of 5/0.35/1. It is found that the content of Gd₂O₃ and impregnation procedure for catalyst preparation significantly affected the catalyst performance. Pt catalyst supported on the Al₂O₃ that was pre-impregnated with Ce and Gd nitrates orderly to 15 wt% CeO₂ and 1.6 wt% Gd₂O₃ was the best catalyst for ATR of gasoline with high reactivity and excellent stability. Within 1000-h ATR of retail gasoline over this catalyst, gasoline conversion was slowly decreased to 95% after 300-h run and then remained at ∼95% throughout the test, while H₂ fraction in reformate remained at ∼67% with a CH₄ fraction less than 0.6%. It is revealed that modification of Al₂O₃ with CeO₂ first and Gd₂O₃ then endowed the produced Pt catalyst with many advantageous effects such as significantly improved and stabilized Pt-CeO₂ interaction, greatly attenuated Pt-sintering, and enhanced oxygen ion conductivity of bulk CeO₂.