'Water Splitting' by Titanium Exchanged Zeolite A.
UTAH UNIV SALT LAKE CITY DEPT OF CHEMISTRY
Pagination or Media Count:
Visually detectable and chromatographically and mass spectrally identified hydrogen gas evolves from titanium III exchanged zeolite A immersed in water and illuminated with visible light. TitaniumIII exchanged zeolite X and zeolite Y do not produce this reaction. A photochemically produced, oxygenated titanium free radical detected by electron spin resonance not previously described is the species in the zeolite that reduces protons to molecular hydrogen. The other product of this reduction step is a nonradical, oxygenated titanium species of probable empirical formula TiO4. Heating the spent oxygenated titanium containing zeolite A under vacuum at 375 C restores over fifty percent of the free radical. Unlike previously reported systems, heating does not restore the original aquotitaniumIII species in the zeolite. Thus a means other than heating must be found to achieve a closed photochemical cycle that harnesses visible solar energy in the production of molecular hydrogen. The titanium exchanged zeolite A does, however, lend itself to a thermolysis of water previously described by Kasai and Bishop. Author
- Industrial Chemistry and Chemical Processing
- Atomic and Molecular Physics and Spectroscopy