Interplay Between the Preparation Parameters and the ORR Performance of "Core-Shell" Carbon Nitride Nano-Electrocatalysts Bearing Bimetal Pt/Co Active Sites

This work introduces a new family of “core-shell” carbon nitride nano-electrocatalysts that consist of a “core” of graphite nanoparticles and a “shell” composed of a carbon nitride matrix. The shell is characterized by a low concentration of nitrogen and embedded bimetal Pt/Co active sites. The influence of the chemical composition of the starting hybrid inorganic-organic precursor and the parameters of the pyrolysis process on the structure, morphology and electrochemical performance of the final products is studied in detail. The chemical composition of the products is determined by ICP-AES and microanalysis. The structure is investigated by powder Xray diffraction and μ-Raman spectroscopy, while the morphology is characterized by HR-TEM. The electrochemical performance of the materials in the ORR is determined by ex-situ measurements with the CV-TFRRDE method. Membraneelectrode assemblies (MEAs) are fabricated using the carbon nitride nano-electrocatalysts at the cathode electrodes. These MEAs are tested in a single fuel cell under operating conditions.