Of great interest is the creation of a lightweight, 3D, mesoporous carbon electrode platform with high-loading of electrochemically or electro-catalytically active species for energy storage and conversion. Nitrogen-doped porous carbon shows outstanding electrocatalysis of oxygen reduction reaction (ORR) and excellent energy storage capability. Nitrogen-doped porous carbons are often prepared by the pyrolysis of nitrogen-rich organics/polymers. Due to a lack of mechanical integrity, a binder must be used to hold as-synthesized microparticulates together onto the substrate leading to an ill-defined porous structure. The binder blocks some of the active sites and adds additional ohmic resistance. We have developed two polymerization methods to covalently graft poly(4-vinylpyridine) conformably on a carbon surface without needing a binder. One is a precipitation method and the other is an aqueous based electro-polymerization method. We have found that pyrolyzed poly(4-vinylpyridine) in the presence of metals can increase char yield as indicated by TGA. The presence of metal promotes the incorporation of nitrogen into the carbon matrix, according to X ray absorption analysis. We have demonstrated that metal-N coordination can be adjusted systematically by metal loading and consequently ORR capability can be tailored. We will discuss the results from the effect of metal loading on metal-N coordination and consequent carbon electronic structure and ORR performance using CV (Cyclic Voltammetry) and RRDE (Rotating Ring Disc Electrode).

Effect of metal-nitrogen coordination on ORR electrocatalysis

253rd National Meeting (2017)

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