Artículos SCI

Different Pt-TiO₂-Nb₂O₅ systems were synthesized and studied in the photocatalytic reforming of glucose for the generation of H₂. The physicochemical properties of the synthesized photocatalysts were analyzed using different characterization techniques from which it was found that fluoridation and sulphation have different effects on the oxides under study such as a protective effect on the crystalline phase in anatase, and greater response in the visible region of the electromagnetic spectrum. The addition of fluorine or sulfates favors the reduction of platinum species on the surface of the semiconductor oxides and a better homogeneity of size and distribution of the particles of this metal. Studies were carried out in the gas phase that allowed the monitoring and quantification of the hydrogen produced from aqueous glucose solutions and it was determined that Pt-F-Nb₂O₅ and Pt-F-TiO₂ are the most efficient materials for the production of hydrogen from this substrate. Similarly, liquid phase studies were carried out with a real sample from a confectionery industry where it was determined that with the material Pt-F-Nb₂O₅ the highest transformation of glucose is obtained, without the formation of any other sugar or intermediate compound, indicating the preferential production of hydrogen during the photocatalytic reaction. The foregoing demonstrates the potential of the evaluated process in obtaining this gas from the recovery of polluting residues derived from the samples under study.

Hydrogen is the ideal energy vector to reduce our fossil-fuels dependency and diminish the climate change consequence. However, current production is still methane based. It is possible to produce hydrogen using bioethanol from the alcoholic fermentation of organic waste by chemical looping processes, but unfortunately current redox systems generate hydrogen with significant traces of CO. In the case of proton exchange membrane fuel cells (PEMFC), hydrogen must be highly purified to produce electricity. Here, high porosity inter-connected Fe2O3 foams doped with 2 wt% Al2O3 were manufactured by the freeze-casting method, obtaining around 5.1 mmol H2$g?1 sample of highly pure hydrogen (<10 ppm of CO) consuming only 3.42 mmol of ethanol on each redox cycles, with no deactivation. This result shows the possibility of using an abundant and inexpensive raw material as the iron oxide to scale-up the direct pure H2 production and facilitates its use in the automotive sector.