A porous, efficient, and durable nonprecious electrocatalyst for the oxygen reduction reaction (ORR) under both alkaline and acidic conditions is synthesized by a green, solvent-free, one-pot, economical, scalable, and template-free strategy. In situ formed graphitic carbon nitride (g-C₃N₄) is utilized as a sacrificial template for constructing the core–shell Fe₃C@NSC electrocatalyst with a highly porous substructure and nanosheet-like morphology. The presence of glucose facilitates the homogeneous distribution of nanoparticles and establishes the nanosheet structure, otherwise agglomeration and formation of nanotubes occur in the Fe₃C@NSC electrocatalyst. Optimizing the synthetic conditions generates a highly active ORR electrocatalyst with a unique mesoporous architecture, large surface area, high nitrogen doping level, encapsulated Fe₃C nanoparticles in NS co-doped carbon layers and multiple exposed edge active centers. The best performing electrocatalyst displays outstanding ORR performance under alkaline conditions with onset potential and half-wave potential (E_1/2) values of 1.059 and 0.938 V vs. the reversible hydrogen electrode (RHE), much higher than those of the state-of-the-art commercial Pt/C (20%), and admirable performance in acidic media. In addition, it exhibits 4e⁻ selectivity, tolerance toward methanol, and superb durability with zero degradation after 12 000 potential cycles under both alkaline and acidic conditions. These exceptional characteristics make the as-synthesized electrocatalyst one of the top-level non-precious ORR electrocatalysts reported to date.

Innovating efficient and robust electrocatalysts with economical production cost for the oxygen reduction reaction (ORR) is of utmost significance for enhancing the energy efficiency of fuel cells and metal–air batteries. Herein, a single-step doping/annealing strategy has been developed for fabricating an Fe–N–C/Fe₃C/C–S–C nanohybrid with a high N-doping level, well-defined mesoporous/microporous architecture, and high density of efficient active sites. The importance of tuning the S-doping into the electrocatalyst carbon framework has been fully elaborated for the first time. Under alkaline conditions, the nanohybrid displayed an exceptional onset potential (E₀) and half-wave potential (E_1/2) of 1.078 and 0.929 V vs. reversible hydrogen electrode (RHE). Furthermore, it manifests a dominant four-electron transfer reaction, marvelous selectivity for the ORR in the presence of methanol, and excellent durability after 15 000 potential cycles with almost zero degradation in performance under both acidic and alkaline conditions. The superb performance is due to the high density of active sites, like FeN_x, FeS_x, Fe₃C, pyridinic-N, graphitic-N, C–S–C, and C–SO_x–C, that efficiently catalyze the ORR. In addition, the high graphitization degree boosts the electron conductivity and corrosion resistance; meanwhile, the high surface area and ideal mesoporosity enhance the mass transfer and facilitate the maximum exposure of the active sites to the electrolyte and reactants.

The inert annealing step during the synthesis of the Ni/MgAl₂O₄catalyst induces positive changes in the catalyst substructure. The obtained catalyst displayed high catalytic activity towards steam methane reforming with low carbon deposition.

A facile and green synthetic strategy is developed in this paper for the construction of an efficient catalyst for the industrially important carbon dioxide reforming of methane, which is also named the dry reforming of methane (DRM). Through controlling the synthetic strategy and Ni content, a high-performance Ni@CeO₂ catalyst was successfully fabricated. The catalyst showed superb efficiency for producing the syngas with high and stable conversions at prolonged operating conditions. Incorporating Ni during the ceria (CeO₂) crystallization resulted in a more stable structure and smaller nanoparticle (NP) size with a more robust interaction with the support than loading Ni on CeO₂ supports by the conventional impregnation method. The H₂/CO ratio was almost 1.0, indicating the promising applicability of utilizing the obtained syngas for the Fischer–Tropsch process to produce worthy chemicals. No carbon deposits were observed over the as-synthesized catalyst after operating the DRM reaction for 50.0 h, even at a more coke-favoring temperature (700 °C). Owing to the superb resistance to coke and sintering, control of the size of the Ni-NPs, uniform dispersion of the active phase, and potent metal interaction with the support, the synthesized catalyst achieved a magnificent catalytic activity and durability during serving for the DRM reaction for extended operating periods.