| AVS 54th International Symposium | |
| Renewable Energy Science & Technology Topical Conference | Wednesday Sessions |
| Session EN+SS+TF-WeM |
| Session: | Catalysis for Hydrogen Storage and the Hydrogen Economy |
| Presenter: | L.M. Petkovic, Idaho National Laboratory |
| Authors: | L.M. Petkovic, Idaho National Laboratory D.M. Ginosar, Idaho National Laboratory K.C. Burch, Idaho National Laboratory H.W. Rollins, Idaho National Laboratory S.N. Rashkeev, Idaho National Laboratory H.H. Farrell, Idaho National Laboratory |
| Correspondent: | Click to Email |
Thermochemical cycles can be used to split water through a series of chemical reactions where the net result is the production of hydrogen and oxygen at much lower temperatures than direct thermal decomposition. When the primary energy source to drive the cycle is nuclear or solar heat, hydrogen can be produced without the need of fossil fuels and without generating gasses considered to be responsible for global warming. The sulfur-iodine (S-I) thermochemical cycle appears promising for producing hydrogen from water. The S-I cycle consists of three simultaneous reactions: the decomposition of hydroiodic acid (HI) to produce hydrogen and generate iodine for recycle, the decomposition of sulfuric acid to produce oxygen and generate sulfur dioxide for recycle, and a main reaction where incoming water and the recycle chemicals react to regenerate HI and sulfuric acid. Both HI and sulfuric acid decomposition reactions are facilitated by heterogeneous catalysts. The high-temperature, harsh chemical reaction conditions of the sulfuric acid decomposition reaction present a significantly challenging environment for catalytic materials. In this work a number of titania (rutile)-supported platinum-group metal (i.e., Pt, Ir, Pd, Ru, and Rh) catalysts were investigated for this reaction. To develop an understanding of the factors that cause catalyst deactivation, density-functional theory-based first-principles calculations and computer simulations for transition metal particles positioned on titania (rutile) were performed. In addition, experimental determination of the activity and stability of activated carbon catalysts for the HI decomposition reaction will also be presented. Results of activated carbon characterization analyses, including surface area, temperature programmed desorption, Boehm's titration results, and contact pH of the activated carbons will be discussed.