Influence of Sulfur on the Pyrolysis of CoTMPP as Electrocatalyst for the Oxygen Reduction Reaction

The following work presents the preparation and investigation of pyrolysed Co porphyrin as an electrocatalyst for the oxygen reduc tion reaction ORR in acid media. A new preparation method which needs no addition of carbon supports, allows the structural investigation of the pyrolysis products by XPS, Raman spectro scopy and X ray diffractometry without any interferences of a carbon support. Rotating Disc Electrode measurements RDE reveal the high ORR activity which is mainly caused by a well developed porosity and a suitable molecular structure of the formed carbon. Thermo gravi metric in vestigation of the pyrolysis process shows that the addition of sul phur to the precursor influences the carbonization of the porphyrin in a favourable way. It has been found that extended graphene layers present a particularly suitable matrix for highly active catalytic centre