Studies on Manganese Compounds as a Model for Water Oxidation in Photosystem II

Please enable javascript in your browser.

Khaksar, Mostafa | 2010

1139 Viewed

Type of Document: M.Sc. Thesis
Language: Farsi
Document No: 41385 (03)
University: Sharif University of Technology
Department: Chemistry
Advisor(s): Mohammadi Boghaei, Davar
Abstract:
In the contest of conversion of water to hydrogen and oxygen there is a need for catalysts which will effectively support the oxidation of water. In nature, photosystem II relies on manganese for the oxidation of water. The water oxidizing complex (WOC) contains a cluster of four manganese atoms. In the past few years, there has been a tremendous surge in research on the synthesis of various manganese compounds aimed at simulating WOC of PS II. In this project, several manganese oxides as heterogeneous catalysts in water oxidation have been synthesized and characterized by FT-IR, X-ray diffraction, TGA, XPS, SEM and BET. Some of these oxides are able to oxidize water in the presence of cerium (IV) ammonium nitrate. Oxygen evolution studies were carried out with a dissolved oxygen meter. The role of Mn(V)=O or Mn(IV)=O as an intermediate is emphasized in the mechanism of water oxidation. This study demonstrates that amorphous manganese oxide is a promising catalyst for water oxidation in artificial photosynthetic systems
Keywords:
Photosystem II ; Water Oxidation Complex ; Heterogeneous Catalysis ; Amorphous Manganese Oxide ; Cerium (IV)Ammonium Nitrate