Nitrogen-doped carbon coated palygorskite as an efficient electrocatalyst support for oxygen reduction reaction

Abstract

An electrocatalyst support, nitrogen-doped graphitic layer (CN x ) coated palygorskite (PLS) (donated as PLS@CN x ), is synthesized by carbonizing the polypyrrole (PPy) coated PLS and is explored for the first time as a cathode electrocatalyst support in proton exchange membrane fuel cell. The structural and chemical properties of the PLS@CN x are investigated by Fourier-Transform infrared spectrometer, thermogravimetric analysis, X-ray diffraction and transmission electron microscopy. The electrocatalytic activity and stability of Pt/PLS@CN x toward oxygen reduction reaction (ORR) are studied by cyclic voltammetry (CV) and steady state polarization measurements. Upon loading Pt (20 wt%), the catalysts exhibit superior catalytic performance during ORR, surpassing the conventional Pt/C (Vulcan XC-72) catalysts. High electrocatalytic activity and good stability can be attributed to the nitrogen atom incorporation and SiO 2 component in PLS.