A redox cycle approach for the production of H2 by two-step methanol reforming

In the present work we studied the catalytic production of pure hydrogen from methanol and water using the spinel-type oxide CoFe2O4 (cobalt ferrite) as electron carrier. CoFe2O4 is an interesting material with an inverse spinel structure, and can be readily prepared by co-precipitation of the two oxides in basic media. The final material was obtained by calcinations, and two different calcination temperatures (Tcalc= 450 and 750°C) have been selected, to yield the corresponding CF450 and CF750 samples. A thorough physico-chemical characterization of the materials as a function of Tcalc was carried out. In fact, Tcalc induces some morphological changes in the material, strongly affecting, by aggregation, particles size and so leading to different catalytic performances. Another important aspect, related to Tcalc, seems to be the surface coke deposition, and this phenomenon should be minimized in order to maximize the hydrogen yield. This work is aimed at establishing the influence of both crystal size and carbon deposition on the catalytic performance, in order to improve the stability of the material though several RedOx cycles.