Iron and nitrogen codoped carbon catalyst with excellent stability and methanol tolerance for oxygen reduction reaction

Abstract

Summary A series of non‐precious metal FexNC electrocatalysts for oxygen reduction reaction (ORR) were successfully synthesized using Fe(NO3)3, glucose, and melamine as the Fe, C, and N sources, respectively. The effects of the pyrolysis temperature and Fe/N contents on the catalytic performances are comprehensively investigated. Electrochemical results reveal that among the FexNC catalysts, Fe1.5NC‐900‐2 pyrolyzed at 900°C with the mass ratio of FeC to melamine being 1:10 proves the highest catalytic performance. The half‐wave potential (E1/2) of ORR was 821 mV (vs reversible hydrogen electrode (RHE)) and only 36 mV lower than that on commercial Pt/C catalyst (857 mV). More importantly, Fe1.5NC‐900‐2 catalyst shows excellent stability and methanol tolerance. After 1000 sequential cycles, the E1/2 on Pt/C catalyst shifts negatively by approximately 60 mV, while for Fe1.5NC‐900‐2 catalyst, this shift is only 28 mV although the number of sequential cycles is increased to 8000. In the presence of methanol, the current decay in the chronoamperometric response at 1000 seconds is only 8% and also much lower than that on Pt/C catalyst (46%). The high catalytic performances arise from the abundant Fe3N active sites embedded in the carbon matrix of the FexNC catalysts. These findings can be used to discuss the catalytic mechanism of ORR on the FexNC catalysts and design the nonprecious metal carbon‐based electrocatalysts for ORR.

Noble‐free oxygen reduction reaction catalyst supported on Sengon wood ( Paraserianthes falcataria L. ) derived reduced graphene oxide for fuel cell application

“…Nonetheless, these values were slightly lower than those of the commercial Pt/C catalyst, which is 0.97 V due to the small d band gap and few vacancies on the atomic transition state of Pt. The positive shift in the onset from 0.805 V with RGO 900 for all catalysts indicated that Fe metal and nitrogen play vital roles in creating active sites for ORR activity . The half wave potential was another parameter for determining the ORR activity of each catalyst.…”

Effects of reaction conditions on one‐step synthesis of methylal via methanol oxidation catalyzed by Mo:Fe(2)/ HZSM ‐5 catalyst

“…The increase in peak intensity was due to the accumulation of metal oxides on the catalyst surface. Analysis of the results (Figure 2) showed that as the reaction temperature increased, the metal oxides on the catalyst accumulated and this affected the electron transfer between iron and molybdenum oxides through the lattice oxygen and metal ions, and reduced the oxidation activity of the catalyst 37 . The selectivity of methylal decreased sharply, especially when the temperature increased to 663 K and this seriously affected the yield of the target product.…”

“…Analysis of the results (Figure 2) showed that as the reaction temperature increased, the metal oxides on the catalyst accumulated and this affected the electron transfer between iron and molybdenum oxides through the lattice oxygen and metal ions, and reduced the oxidation activity of the catalyst. 37 The selectivity of methylal decreased sharply, especially when the temperature increased to 663 K and this seriously affected the yield of the target product. This also showed that the reaction temperature of this type of catalyst should be controlled at 663 K in the process of preparing methylal in a onestep process with methanol.…”

Co‐N‐doped hierarchically ordered macro/mesoporous carbon as bifunctional electrocatalyst toward oxygen reduction/evolution reactions

“…Figure 5A and Table S2 exhibited that as-prepared catalysts mainly consisted of C, O, N, and Co. Nitrogen-doped acts a pivotal part in the electrocatalytic activity, which had been studied by numerous researchers. 39,40 The high-resolution N 1s spectrum of N-OMC, Co-N-OMC, and Co-N-3DOM/mC ( Figure 5B) could be fitted by four peaks corresponding to graphitic-N, pyrrolic-N, pyridinic-N, and pyridinic-N-oxide. [41][42][43] The high content of graphitic-N and pyridinic-N of Co-N-OMC and Co-N-3DOM/mC enhanced the catalytic performance.…”