Replacement of precious platinum catalyst with efficient and cheap bifunctional alternatives would be significantly beneficial for electrocatalytic oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) and the application of these catalysts in fuel cells is highly crucial. Despite numerous studies on electrocatalysts, the development of bifunctional electrocatalysts with comparatively better activity and low cost remains a big challenge. In this paper, we report a nanomaterial consisting of nanocactus-shaped Co₃O₄ grown on carbon nanotubes (Co₃O₄/CNTs) and employed as a bifunctional electrocatalyst for the simultaneous catalysis on ORR, and OER. The Co₃O₄/CNTs exhibit superior catalytic activity toward ORR and OER with the smallest potential difference (0.72 V) between the $${{\boldsymbol{E}}}_{{{\boldsymbol{j}}}_{{\bf{10}}}}$$E j 10 (1.55 V) for OER and E_1/2 (0.83 V) for ORR. Thus, Co₃O₄/CNTs are promising high-performance and cost-effective bifunctional catalysts for ORR and OER because of their overall superior catalytic activity and stability compared with 20 wt% Pt/C and RuO₂, respectively. The superior catalytic activity arises from the unique nanocactus-like structure of Co₃O₄ and the synergetic effects of Co₃O₄ and CNTs.

Energy management strategy (EMS) has a great impact on securing fuel cell durability, battery charge sustenance, and fuel saving in fuel cell hybrid electric vehicles (FCHEVs). This study aims to develop EMS that can be applied in real-time to satisfy above conditions. Real time power separation was performed using rule-based EMS. A genetic algorithm (GA) was implemented to calculate the optimal battery charge/discharge criterion that simultaneously satisfies the minimum hydrogen consumption rate, battery charge rate preservation, and high fuel cell efficiency. The battery charge/discharge parameter values vary according to driving patterns, and in this paper, typical suburban, urban, and highway driving conditions are considered. For the real-time application of this research method, the effectiveness was demonstrated by applying the driving conditions of unknown patterns. The effect on the initial battery SOC on EMS was analyzed, and in order to verify the superiority of this method, it was compared and analyzed with EMS results using dynamic programming and fuzzy logic under the same driving cycles. The effectiveness of this research method was verified through simulation, and it was confirmed through experiments for real-time application. Since there is a limit to the experiment using an actual fuel cell vehicle, the experiment was performed using a fuel cell and battery. This method can be applied to real fuel cell vehicles in the same way.

The metal-free nitrogen-doped graphitic-carbon@graphene (Ng-C@G) is prepared from a composite of polyaniline and graphene by a facile polymerization following by pyrolysis for electrochemical oxygen reduction reaction (ORR). Pyrolysis creates a sponge-like with ant-cave-architecture in the polyaniline derived nitrogenous graphitic-carbon on graphene. The nitrogenous carbon is highly graphitized and most of the nitrogen atoms are in graphitic and pyridinic forms with less oxygenated is found when pyrolyzed at 800 °C. The electrocatalytic activity of Ng-C@G-800 is even better than the benchmarked Pt/C catalyst resulting in the higher half-wave potential (8 mV) and limiting current density (0.74 mA cm⁻²) for ORR in alkaline medium. Higher catalytic performance is originated from the special porous structure at microscale level and the abundant graphitic- and pyridinic-N active sites at the nanoscale level on carbon-graphene matrix which are beneficial to the high O₂-mass transportation to those accessible sites. Also, it possesses a higher cycle stability resulting in the negligible potential shift and slight oxidation of pyridinic-N with better tolerance to the methanol.