Developing nonprecious carbon electrocatalysts as alternatives to platinum for cathodic oxygen reduction reaction in fuel cells is of signifi- cance. Herein, an efficient precursor-controlled synthesis strategy based ...Developing nonprecious carbon electrocatalysts as alternatives to platinum for cathodic oxygen reduction reaction in fuel cells is of signifi- cance. Herein, an efficient precursor-controlled synthesis strategy based on extremely rapid nucleation and deposition process assisted by the liquid nitrogen freeze drying method is explored to anchor cheap iron-EDTA complex evenly dispersed on graphene to realize mJcrostructural homogeneity of the derived Fe-N-C oxygen reduction electrocatalyst. The prepared electrocatatyst possesses excellent performance including high activity with more positive onset and half-wave potential, a long-term stability, and anti-poisoning effect compared to commercial Pt/C. The activity correlates well with the unique sheet-shaped morphology, high surface area, hierarchical porous structure, and the introduction of Fe-Nx/C species. Especially, both the assembled practical alkaline and acid fuel cells based on the synthesized cathode catalysts reveal excellent performance with high open-circuit voltage and power density.展开更多
Efficient oxygen electrocatalysts are the key elements of numerous energy storage and conversion devices, including fuel cells and metal-air batteries. In order to realize their practical applications, highly efficien...Efficient oxygen electrocatalysts are the key elements of numerous energy storage and conversion devices, including fuel cells and metal-air batteries. In order to realize their practical applications, highly efficient and inexpensive non-noble metal-based oxygen electrocatalysts are urgently required. Herein, we report a novel iron-chelated urea-formaldehyde resin hydrogel for the synthesis of Fe-N-C electrocatalysts. This novel hydrogel is prepared using a new instantaneous （20 s） one-step scalable strategy, which theoretically ensures the atomic-level dispersion of Fe ions in the urea-formaldehyde resin, guaranteeing the microstructural homogeneity of the electrocatalyst. Consequentl~ the prepared electrocatalyst exhibits higher catalytic activity and durability in the oxygen reduction （ORR） and evolution （OER） reactions than the commercial Pt/C catalyst. Furthermore, the above catalyst also shows a much better performance in rechargeable Zn-air batteries, including higher power density and better cycling stability. The developed synthetic approach opens up new avenues toward the development of sustainable active electrocatalysts for electrochemical energy devices.展开更多
基金This work was financially supported by Ministry of Science and Technology of China （Nos. 2026YFB0200203 and 2017YFA0206704）, National Program on Key Basic Research Project of China （No. 2014CB932300）, Strategic Priority Research Program of the Chinese Academy of Sciences （No. XDA09010404）, Technology and Industry for National Defense of China （No. JCKY2026130B010）,and National Natural Science Foundation of China （Nos. 51771177, 21422108 and 51472232）.
文摘Developing nonprecious carbon electrocatalysts as alternatives to platinum for cathodic oxygen reduction reaction in fuel cells is of signifi- cance. Herein, an efficient precursor-controlled synthesis strategy based on extremely rapid nucleation and deposition process assisted by the liquid nitrogen freeze drying method is explored to anchor cheap iron-EDTA complex evenly dispersed on graphene to realize mJcrostructural homogeneity of the derived Fe-N-C oxygen reduction electrocatalyst. The prepared electrocatatyst possesses excellent performance including high activity with more positive onset and half-wave potential, a long-term stability, and anti-poisoning effect compared to commercial Pt/C. The activity correlates well with the unique sheet-shaped morphology, high surface area, hierarchical porous structure, and the introduction of Fe-Nx/C species. Especially, both the assembled practical alkaline and acid fuel cells based on the synthesized cathode catalysts reveal excellent performance with high open-circuit voltage and power density.
文摘Efficient oxygen electrocatalysts are the key elements of numerous energy storage and conversion devices, including fuel cells and metal-air batteries. In order to realize their practical applications, highly efficient and inexpensive non-noble metal-based oxygen electrocatalysts are urgently required. Herein, we report a novel iron-chelated urea-formaldehyde resin hydrogel for the synthesis of Fe-N-C electrocatalysts. This novel hydrogel is prepared using a new instantaneous （20 s） one-step scalable strategy, which theoretically ensures the atomic-level dispersion of Fe ions in the urea-formaldehyde resin, guaranteeing the microstructural homogeneity of the electrocatalyst. Consequentl~ the prepared electrocatalyst exhibits higher catalytic activity and durability in the oxygen reduction （ORR） and evolution （OER） reactions than the commercial Pt/C catalyst. Furthermore, the above catalyst also shows a much better performance in rechargeable Zn-air batteries, including higher power density and better cycling stability. The developed synthetic approach opens up new avenues toward the development of sustainable active electrocatalysts for electrochemical energy devices.
