Modified Electronic Structure and Enhanched Catalytic Activity of Cobalt Tetraphenylporphirin Supported by Titanium Dioxide

Article abstract of DOI:10.1021/j100461a006

The electronic structure and the catalytic activity of cobalt tetraphenylporphirin supported on titanium dioxide (CoTPP/TiO2) were studied in order to reveal the electronic interaction between the oxide and the planar complex, which can modify the nature of the latter substance.CoTPP/TiO2 showed a sharp isotropic ESR signal at a g value of 2.003 and a UV band around 590 nm, values which were completely different from those of the unsupported CoTTP.The formation of an anionic radical, which has an odd electron in the porphyrin ring, is suggested.CoTTP?TiO2 showed remarkable catalytic activity for the reduction of nitric oxide to nitrous oxide and molecular nitrogen even at 50 deg C with hydrogen, which was found to be adsorbed on CoTTP/TiO2.The activity was much accelerated at 150 deg C, where a successive reduction of nitric oxide in the sequence NO --> N2O --> N2 was clearly indicated.