One-step synthesis of dual-transition metal substitution on ionic liquid based N-doped mesoporous carbon for oxygen reduction reaction

Abstract

Nitrogen (N)-doped ordered mesoporous carbons (OMCs) with a dual transition metal system were synthesized as non-Pt catalysts for the ORR. The highly nitrogen doped OMCs were prepared by the precursor of ionic liquid (3-methyl-1-butylpyridine dicyanamide) for N/C species and a mesoporous silica template for the physical structure. Mostly, N-doped carbons are promoted by a single transition metal to improve catalytic activity for ORR in PEMFCs. In this study, our N-doped mesoporous carbons were promoted by the dual transition metals of iron and cobalt (Fe, Co), which were incorporated into the N-doped carbons lattice by subsequently heat treatments. All the prepared carbons were characterized by via transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). To evaluate the activities of synthesized doped carbons, linear sweep was recorded in an acidic solution to compare the ORR catalytic activities values for the use in the PEMFC system. The dual transition metal promotion improved the ORR activity compared with the single transition metal promotion, due to the increase in the quaternary nitrogen species from the structural change by the dual metals. The effect of different ratio of the dual metals into the N doped carbon were examined to evaluate the activities of the oxygen reduction reaction.

Ni Nanoparticles on Ni Core/N-Doped Carbon Shell Heterostructures for Electrocatalytic Oxygen Evolution

“…The chemical structures of active species in the nanocatalysts are another critical factor for determining catalytic properties . Transition metal-based active species can be atomically attached onto carbon-based nanomaterials via M–N x –C and M–O x –N graphene , which exhibited distinct catalytic behaviors. , The metal ions coordinately grafted to heteroatoms in carbon-based networks make them more resistant to sintering during the catalytic reaction. The atomically dispersed active species at the surfaces of nanomaterials enhanced the catalytic activity and selectivity .…”

Cobalt‐Based Active Species Molecularly Immobilized on Carbon Nanotubes for the Oxygen Reduction Reaction

“…The deconvoluted N 1s XPS spectrum of N‐CNT exhibited the presence of pyridinic N atoms as a majority as well as pyrrolic and quaternary N atoms (Figure e) . After the hybridization of N‐CNT with Co II (acac) 2 , the deconvoluted N 1s XPS spectrum of Co–N‐CNT exhibited a new peak at BE=399.3 eV, which is attributed to Co−N bonds .…”