Activity and stability of sulfuric acid decomposition catalysts for thermochemical water splitting cycles

Thermochemical cycles produce hydrogen through a series of chemical reactions where the net result is the production of hydrogen and oxygen from water at much lower temperatures than from direct thermal decomposition. The sulfur-based family of thermochemical cycles appears to have significant technical viability for producing hydrogen. A study on the activity and stability of supported Pt catalysts for the decomposition of sulfuric acid was carried out. Supports studied were TiO₂ and α-Al₂O₃ with Pt loadings of 0.1 and 1 wt %. The Pt/TiO₂ catalysts had the greatest stability and Pt loadings of 1 wt % provided the highest product yields. Although relatively stable, the Pt/TiO₂ catalyst did not display long term stability and preliminary results suggest that the catalyst was not stable at ≥ 850°C. This catalyst be appropriate for the sulfuric acid decomposition reaction where temperatures. This is an abstract of a paper presented at the AIChE Annual Meeting and Fall Showcase (Cincinnati, OH 10/30/2005-11/4/2005).