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

An electrocatalyst support, nitrogen-doped graphitic layer (CNx) coated palygorskite (PLS) (donated as PLS@CNx), 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@CNx are investigated by Fourier-Transform infrared spectrometer, thermogravimetric analysis, X-ray diffraction and transmission electron microscopy. The electrocatalytic activity and stability of Pt/PLS@CNx 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 SiO2 component in PLS.

► An electrocatalyst support, PLS@CNx composite nanoparticle, was fabricated by carbonizing polypyrrole-PLS hybridized precursor.
► Pt/PLS@CNx exhibited the higher activity and better stability than Pt/C for the oxygen reduction.
► High oxygen reduction electrocatalytic activity and good stability are attributed to the nitrogen atom incorporation and SiO2 component in PLS.