PYROLYSIS BEHAVIOR OF METALLOPORPHYRINS .2. A MOSSBAUER STUDY OF PYROLYZED FE(III) TETRAPHENYLPORPHYRIN CHLORIDE

Fe(III) tetraphenylporphyrin chloride (FeClTPP) has been pyrolysed at different temperatures (450-850-degrees-C) for different lengths of time (10-260 min). Some of the samples were mixed with carbon black in a 50/50 (w/w) proportion. Mossbauer spectra were obtained for these catalyst powders. The spectra reveal a number of different sites, occurring with different relative abundance depending on the pretreatment. XPS and electrochemical measurements have also been performed using the same samples. The electrocatalytic properties can be described as a function of the abundance of the various sites and the XPS data were used to support the interpretation.