NOVEL NANO-SCALE Au/α-Fe_2O_3 CATALYST FOR THE PREFERENTIAL OXIDATION OF CO IN BIOFUEL REFORMATE GAS

摘要

Au/α-Fe_2O_3 catalyst was synthesized using a modified co-precipitation method to generate an inverse catalyst model. The effects of introducing CO_2 and H_2O during preferential oxidation (PROX) of CO were investigated. The goal of this work was ≥99.8% CO conversion at 80°C. There was an increase in the conversion at all temperatures with the introduction of CO_2 and 100% of the CO was converted at the target temperature of 80°C for any amount of CO_2. Furthermore, there was an increase in conversion to 100% for water fractions ranging from 3% to 10%. Finally, for realistic conditions of (bio-)fuel reforming, 24% CO_2 and 10% water, 99.85% conversion was achieved. A long-term test of 200 hours showed no significant deactivation of the catalyst at a temperature of 80°C in presence of 24% CO_2 and 3% water. The mechanism for PROX is not known definitively, however, current literature believes the gold particle size is the key. In contrast, we emphasize the tremendous role of the support particle size.