Effects Of Preparation On Electrocatalytic Performance Of Co-PPy-TsOH/C Towards Oxygen Reduction Reaction

Oxygen reduction reaction (ORR) on the cathode of proton exchange membrane fuel cells (PEMFCs) is one of the main performance determining steps. So, novel cathode electro-catalysts with high catalytic activity and excellent durability are badly in need. Due to high cost and limited resources of noble metal catalysts, such as Pt catalyst, non-noble metal catalysts attracted much attention in recent years.As a kind of novel non-noble catalysts, Co-PPy-TsOH/C exhibits excellent catalytic activity and durability towards ORR and have received great interest. This paper systematically studied the effect of preparation conditions on electrocatalytic performance of Co-PPy-TsOH/C, including Co loading and oxidant species. The effects of them have been comparatively investigated by electrochemical techniques, such as cyclic voltammetry (CV), rotating disk electrode (RDE) and single cell test. Then, various physicochemical analysis methods, such as infrared spectroscopy (IR), Raman spectra (Raman), X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and X-ray absorption fine stucture (XAFS) have been employed to understand the results.It was found that Co-PPy-TsOH/C catalyst prepared with 2 wt% Co loading and ferric chloride as oxidant showed the best ORR activity:the peak potential for ORR is 0.698 V and 0.686 V, the electron transfer number is 3.90 and 3.84 and the maximal power density is 150 mW/cm2 and 200 mW/cm2, respectively.