Functional nanomaterials including noble metal nano-alloy and heteroatom-doped carbon materials were designed, fabricated, comprehensively characterized by physical and electrochemical methods and further applied in electrocatalyzing reactions in low-temperature fuel cells. The mechanisms concerning the oxygen reduction reaction (ORR) catalytic performance enhancement resulting from different doped nitrogen configurations were also studied by density functional theory (DFT) calculations. The research provides strong theoretical support for the catalytic activity enhancement. The research outcome also has high potential to improve the catalysts of fuel cells with high catalytic activity, facile synthesis method and low cost. Highly dispersed and active PdNi alloy supported on reduced graphene oxide (rGO) was prepared by a simultaneous reduction method using NaBH4 as the reductant followed by annealing in H2 at 500 °C. The as-prepared PdNi alloy was further applied to catalyze formic acid electrooxidation. Different characterization methods verified that H2 annealing at appropriate temperature had a significant influence on both physiochemical composition and electrocatalytic performance of the synthesized catalysts. H2 annealing at 500 °C facilitated formation of PdNi alloy without agglomeration of the nano-sized metallic catalyst, while without H2 treatment Ni was found predominantly in the form of Ni(OH)2 and NiOOH. Cyclic voltammetry (CV) and chromoamperometric (CA) testing demonstrated that when compared with the sample without H2 treatment, PdNi/rGO after H2 annealing exhibited better catalytic activity and stability towards formic acid electrooxidation. The enhanced performance can be explained by modification of the electronic structure of Pd by alloying with Ni and large specific surface area and excellent electronic conductivity of the rGO support.Developing metal-free catalysts for ORR is a great challenge for the wide application of fuel cells. Nitrogen and sulfur codoped carbon with remarkably high nitrogen content up to 13.00 at % was successfully fabricated by pyrolysis of homogeneous mixture of exfoliated graphite flakes and traditional ionic liquid 1-butyl-3-methyl-imidazolium bis(trifluoromethanesulfonyl)imide ([Bmim][Tf2N]). The exfoliated graphite flakes served as a structure-directing substance as well as additional carbon source in the fabrication. It was demonstrated that the use of graphite flakes increased the nitrogen-doping level, optimized the composition of active nitrogen configurations, and enlarged the specific surface area of the catalyst. Electrochemical characterization revealed that the as-prepared N and S codoped carbon exhibited superior catalytic activity towards ORR under both acidic and alkaline conditions. Particularly in alkaline solution, the material compared favorably to the commercial 20 wt % Pt/C catalyst via four-electron transfer pathway with better ORR selectivity. The excellent catalytic activity is mainly ascribed to high nitrogen-doping content, appropriate constitution of active nitrogen configurations, large specific surface area, and synergistic effect of N and S codoping. Different from the preparation of N and S codoped carbon in which precursors were hydrophobic, nitrogen-doped graphene was also successfully prepared by selecting traditional hydrophilic ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim]BF4), and graphene oxide (GO) as precursors for carbonization under inert gas atmosphere. The [Bmim]BF4 could be adsorbed on the surface of GO spontaneously by electrostatic attraction when vigorously stirred in water and served as restacking protectant, nitrogen source as well as additional carbon source during the subsequent pyrolytic process. The effect of pyrolysis temperature on the physicochemical properties and ORR catalytic activities of the synthesized catalysts was also discussed in detail. It was found that 900 °C was the optimal pyrolysis temperature. Higher temperature would destroy the graphene morphology and lead to removal of the doped N element as well, while lower temperature would yield poor electronic conductivity due to incomplete reduction of GO. Based on the electrochemical test results, the synthesized nitrogen-doped graphene exhibited excellent electrocatalytic activity toward ORR in alkaline conditions with regard to current density, selectivity and durability. In the theoretical study, DFT calculations were performed to investigate the mechanism of ORR performance enhancement resulting from doping by different N configurations. The results showed that both Pyridinic N-edge and Graphitic N-inside, having 7 and 5 active sites, respectively, had great potential to perform excellent catalytic activity towards ORR with the energy gap of Graphitic N-inside being 0.01 eV narrower than that of Pyridinic N-edge. Based on the experimental and calculation results, the beneficial properties of as-prepared nitrogen-doped graphene are attributed to superior conductivity of graphene, high nitrogen-doping content and high proportion of active graphitic N and pyridinic N. The present experimental and theoretical works show that PdNi alloy supported on rGO and heteroatom-doped carbon materials are promising anodic and cathodic catalysts of fuel cells, respectively. The new knowledge generated is of fundamental importance as well as potential application value for developing effective catalysts for low-temperature fuel cells.