N-doped carbon xerogels from urea-resorcinol-formaldehyde as carbon matrix for Fe-N-C catalysts for oxygen reduction in fuel cells

Platinum group metal-free catalysts have been intensively investigated in the last decades as an alternative to platinum with aim of lowering cost polymer electrolyte fuel cells. In particular, iron-nitrogen-carbon (Fe-N-C) has proved be most active towards oxygen reduction reaction. For practical application, a hierarchical pore structure is required, micropores favouring creation sites and larger pores (meso- macropores) facilitating mass transport. this work, carbon xerogels are hosting iron nitrogen species obtained by template-free method. The introduction one-step polymerization urea resorcinol formaldehyde for first time field varying relative content reactants. urea/resorcinol ratio greatly influences Fe-N-C catalyst ORR electrocatalytic activity thereof. favored balanced where porosity well developed relatively high contents incorporated xerogel. acid (0.5 M H2SO4), onset potential 0.82 V vs. RHE, number exchanged electrons very close 4 (i.e. full conversion water) low Tafel slope 71 mV dec−1, series, possessing best compromise sites. Fuel cell tests corroborate that porous shows performance.