Mehmood, Asad Pampel, Jonas Ali, Ghulam Ha, Heung Yong Ruiz-Zepeda, Francisco Fellinger, Tim-Patrick 2024-01-19T23:03:44Z 2024-01-19T23:03:44Z 2021-09-03 2018-03-26 1614-6832 https://pubs.kist.re.kr/handle/201004/121584 Iron-or cobalt-coordinated heteroatom doped carbons are promising alternatives for Pt-based cathode catalysts in polymer-electrolyte fuel cells. Currently, these catalysts are obtained at high temperatures. The reaction conditions complicate the selective and concentrated formation of metal-nitrogen active sites. Herein a mild procedure is introduced, which is conservative toward the carbon support and leads to active-site formation at low temperatures in a wet-chemical metal-coordination step. Active-site imprinted nitrogen doped carbons are synthesized via ionothermal carbonization employing Lewis-acidic Mg2+ salt. The obtained carbons with large tubular porosity and imprinted N-4 sites lead to very active catalysts with a half-wave potential (E-1/2) of up to 0.76 V versus RHE in acidic electrolyte after coordination with iron. The catalyst shows 4e-selectivity and exceptional stability with a half-wave potential shift of only 5 mV after 1000 cycles. The X-ray absorption fine structure as well as the X-ray absorption near edge structure profiles of the most active catalyst closely match that of iron(II) phthalocyanine, proving the formation of active and stable FeN4 sites at 80 degrees C. Metal-coordination with other transition metals reveals that Zn-Nx sites are inactive, while cobalt gives rise to a strong performance increase even at very low concentrations. English WILEY-V C H VERLAG GMBH N-C CATALYSTS HIGHLY EFFICIENT O-2 REDUCTION SURFACE-AREA IRON FE PERFORMANCE GRAPHENE POLYANILINE ALKALINE Facile Metal Coordination of Active Site Imprinted Nitrogen Doped Carbons for the Conservative Preparation of Non-Noble Metal Oxygen Reduction Electrocatalysts Article 10.1002/aenm.201701771 1 ADVANCED ENERGY MATERIALS, v.8, no.9 ADVANCED ENERGY MATERIALS 8 9 scie scopus 000429318400006 2-s2.0-85038116685 Chemistry, Physical Energy & Fuels Materials Science, Multidisciplinary Physics, Applied Physics, Condensed Matter Chemistry Energy & Fuels Materials Science Physics Article N-C CATALYSTS HIGHLY EFFICIENT O-2 REDUCTION SURFACE-AREA IRON FE PERFORMANCE GRAPHENE POLYANILINE ALKALINE active site imprinting FeN4 active sites metal-nitrogen coordination non-noble metal catalysts oxygen reduction reaction