Fig. 1. N2 adsorption-desorption isotherms and TEM image of XC72R CB.

Fig. 2. Novel nanocarbon materials as the support for PEMFCs.

Fig. 3. The effect of the pore structure of nanocarbon support on the supported metal catalysts.

Fig. 4. (a) Schematic illustration for the effect of the structural regularity of the carbon support on the activity of Pt and (b) cyclic voltagrammograms of ethanol oxidation on Pt/WMCs and Pt/CMK-3. Reproduced with permission from Ref. [57], Copyright 2010 Elsevier. (c) Cyclic voltammetry curves of the as-prepared Pt/WMCs and Pt/CMK-3; (d) schematic diagram of highly OMC (CMK-3 and FDU-15) with different nanopore arrays and (e) comparison of electrochemical performance of Pt/CMK-3 and Pt/FDU-15. Reproduced with permission from Ref. [59], Copyright 2011 Royal Society of Chemistry.

Fig. 5. SEM (a), TEM (b), and HAADF-STEM (c,d) images of Fe/N-GPC; (e) Schematic diagram of molecular diffusion in an hierarchical pore structure. Reproduced with permission from Ref. [74], Copyright 2017 American Chemical Society.

Fig. 6. CV curve (a) and polarization curve (b) of Pt/WMC-F0 and Pt/WMC-F4; (c) Schematic of the effect of pore diameter of WMCs on the accessibility of Pt nanoparticles; (d) Comparison of the peak current density for EOR of mesoporous carbon with different pore diameters under different temperatures. Reproduced with permission from Ref. [78], Copyright 2010 Elsevier.

Fig. 7. The effect of the heteroatom doping of nanocarbon supports on the properties of supported metal catalysts.

Fig. 8. (a) Schematic diagram of four types of N species in NCs, namely, pyridinic nitrogen (A), pyrrolic nitrogen (B), quaternary nitrogen (C), and pyridine-N-X (D); (b) Comparison of polarization curves; (c) Electrochemical performance of Pd/C, Pd@N-C NFs, and N-C NFs. Reproduced with permission from Ref. [97], Copyright 2019 Royal Society of Chemistry; (d) CV curves of Pt/NMC-1 and Pt/NMC-2 in an acid electrolyte. Reproduced with permission from Ref. [93], Copyright 2018 Elsevier.

Fig. 9. Comparison of the relative potential surface energy of different types of N in nitrogen-doping graphitic carbon materials as calculated by DFT. Reproduced with permission from Ref. [104], Copyright 2020 American Chemical Society.

Fig. 10. Comparison of specific activity (a) and mass activity (b) of Pt/C and Pt@CNx/CNT before and after ADT. Reproduced with permission from Ref. [121], Copyright 2015 American Chemical Society.

Fig. 11. Schematic diagram of H2SO4/HNO3, AEPTMS, and H2O2 oxidatively modifying the OMC surface. Reproduced with permission from Ref. [150], Copyright 2012 Elsevier.

Fig. 12. (a) Mass activity comparison of Pt/CB and Pt/CB_O before and after the ADT test; (b) Schematic diagram of the particle size changes of Pt/CB and Pt/CB_O during ADT. Reproduced with permission from Ref. [155], Copyright 2016 Elsevier.

Fig. 13. Schematic diagram of the structure and performance of the Pt/S-C catalyst. Reproduced with permission from Ref. [162], Copyright 2020 Elsevier.

Fig. 14. (a) Schematic diagram for the preparation of the Pt/S-MWCNTs catalyst and (b,c) CV and current-time curves of Pt/S-MWCNT (A), Pt/AO-MWCNT (B), and commercial Pt/C (C) catalysts. Reproduced with permission from Ref. [166], Copyright 2017 Royal Society of Chemistry.

Fig. 15. (a) Schematic diagram for the preparation of the Pd/N-P-G catalyst; (b) Comparison of CV curves of different catalysts in 1 M KOH; (c) Comparison chart of the ECSA values of different catalysts. Reproduced with permission from Ref. [170], Copyright 2019 Elsevier.

Fig. 16. The mechanism of CO resistance and the long-term durability of functional metal carbides as the electrocatalyst support.

Fig. 17. (a) Schematic description for adsorbed CO on Pt and surface hydroxyls formed on WC with Pt/WC-C as the catalyst; (b) Schematic diagram of the preparation of the Pt@WC/OMC nanocomposite catalyst. Reproduced with permission from Ref. [200], Copyright 2015 Elsevier. (c) The MOR activity ratio between Pt/WC-C electrocatalysts with different surface areas and the commercial Pt/C.

Fig. 18. (a) ORR test curves of HMG/WC/Pt and Pt/C (1st and 2000th cycles); (b) Mass activity diagrams of HMG/WC/Pt and Pt/C; the CV curve of Pt/C (c) and HMG/WC/Pt (d) before and after 2000 cycles. Reproduced with permission from Ref. [191], Copyright 2016, Elsevier. a electrochemical surface area (m2 g-1), b limiting diffusion current (%), c mass activity (mA mgPt-1).

Fig. 19. (a) Comparison chart of the ECSA and current density of Pt/SiC and Pt/C single cells and (b) interface structure diagram of Pt/SiC and Pt/C electrodes before and after the AST test. Reproduced with permission from Ref. [223], Copyright 2017 Elsevier.