Kim, Minhyoung Kim, Hee Soo Yoo, Sung Jong Yoo, Won Cheol Sung, Yung-Eun 2024-01-20T02:03:15Z 2024-01-20T02:03:15Z 2021-09-01 2017-02-28 2050-7488 https://pubs.kist.re.kr/handle/201004/123043 The microporous structure of Fe-N-doped carbon (Fe-N-C) catalysts plays a pivotal role in the oxygen reduction reaction (ORR) because the catalytically active N-coordinated Fe ion sites are located within accessible micropores (<2 nm). However, the distinct role of carbon support microporosity in the formation of catalytic sites in Fe-N-C catalysts remains unclear. Here, we report the effect of the pre-defined microporosity of the parent carbon support on the catalytic site density resulting from Fe-N-C catalyst synthesis, and its ultimate effect on ORR activity. The porosity, pore size distribution, and specific surface area of the carbon supports are initially controlled by using hot CO2 treatment. Then, Fe and N are doped into these supports by precursor impregnation and subsequent pyrolysis. In the synthesized Fe-N-C catalysts, the more developed microporosity in the parent carbon supports facilitates more iron and nitrogen contents, especially pyridinic nitrogen, and Fe-N-Cs derived from carbon supports with higher microporosities show enhanced ORR activity, strongly suggesting that a high catalytic site density can be achieved by utilizing carbon supports with well-developed microporosities. The most active Fe-N-C catalyst prepared using our synthetic route exhibits ORR activity comparable to that of a commercial Pt-based catalyst in alkaline media. English ROYAL SOC CHEMISTRY ELECTROLYTE FUEL-CELLS ACTIVE-SITES CATHODE CATALYST FE/N/C CATALYSTS ELECTROCATALYSTS PERFORMANCE ACID ELECTROREDUCTION CHALLENGES STABILITY The role of pre-defined microporosity in catalytic site formation for the oxygen reduction reaction in iron- and nitrogen-doped carbon materials Article 10.1039/c6ta10679j 1 JOURNAL OF MATERIALS CHEMISTRY A, v.5, no.8, pp.4199 - 4206 JOURNAL OF MATERIALS CHEMISTRY A 5 8 4199 4206 scie scopus 000395309800049 2-s2.0-85013858228 Chemistry, Physical Energy & Fuels Materials Science, Multidisciplinary Chemistry Energy & Fuels Materials Science Article ELECTROLYTE FUEL-CELLS ACTIVE-SITES CATHODE CATALYST FE/N/C CATALYSTS ELECTROCATALYSTS PERFORMANCE ACID ELECTROREDUCTION CHALLENGES STABILITY