Production of hydrogen from renewable resources (e.g., biomass) is considered an effective approach to mitigating the environmental problems caused by pollutant emissions from fossil fuels. There is a great deal of interest in Pt/TiO2 because of its promising catalytic prospects in applications of hydrogen production from biomass. However, one important problem should be overcome is that CO as a by-product that will significantly impair the catalytic performance even the presence of carbon monoxide (CO) is as low as only 5-10 ppm. In the present paper, we aimed to fabricate CO poisoning resistant Pt/TiO2 catalyst by doping Pt onto nano-size mesoporous TiO2 and investigate its H2 generation performance in steam reforming reactions.
Nano-size mesoporous TiO2 and 0.5, 1.0, and 2.0% wt Pt-doped, nano-size mesoporous TiO2 were synthesized by a hydrolyzing followed by sintering process. Adsorption isotherms of carbon monoxide (CO) on the synthesized mesoporous TiO2 and on Pt/TiO2 were measured at temperatures 308K, 323K, 348K, 373K, 398K, and 423K and pressures up to 700 mmHg. The 0.5% wt Pt/TiO2 catalyst resulted in better CO adsorption than those which were tested on the nano-size mesoporous TiO2 support. The amounts of CO adsorbed with 1.0% wt and 2.0% wt Pt/TiO2 catalysts were found to be larger than those on nano-size mesoporous TiO2. All measured adsorption isotherms of CO were correlated to fit adsorption models Sips, Toth, and UNILAN in the experimental temperature/pressure range. Sips and Toth models were found to be more accurate for presenting CO adsorption on Pt/TiO2. It suggests that the 0.5% wt Pt/TiO2 catalyst have potentially good CO poisoning resistivity within a wide temperature range. Steam reforming of glucose and methanol under different experimental condition were utilized to generate H2 on the synthesized Pt/TiO2. And for comparison purposes, 5% Pt/Al2O3 was applied as well. It is found that the synthesized low content Pt/TiO2 is more cost-effective.