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Nitrogen‐doped graphitic carbon materials have been widely used as a catalyst support in the methanol oxidation reaction (MOR). In this study, we report the role of three‐dimensionally architectured in‐situ N‐doped vertically aligned carbon nanofibers (VACNF) as a catalyst support for MOR in acidic and alkaline media. The abundant graphitic edge sites at the sidewall of N‐doped VACNF strongly anchor the deposited platinum group metal (PGM) catalysts and induce a partial electron transfer between the PGM catalysts and support. Density Functional Theory (DFT) calculations reveal that the strong metal‐support interaction substantially increases the adsorption energy of OH, particularly near the N‐doping sites, which helps to compete and remove the adsorbed intermediate species generated during MOR. The PGM catalysts on N‐doped VACNF support exhibits CO stripping at lower potentials comparing to the commercial Vulcan carbon support and presents an enhanced electrocatalytic performance and better durability for MOR. [ABSTRACT FROM AUTHOR]

Manganese (Mn) nitrides are important nitrogen (N) carriers for small‐scale intermittent ammonia (NH3) synthesis. However, only 3∼8 % of lattice N are converted into NH3. In this study, the geometric and electronic structures of well‐defined Mn4N and Mn2N lattices were altered using transition metal heteroatoms (Cr, Fe, Co, Ni, Mo) to understand the driving force behind lattice N diffusion and extraction. Density Functional Theory (DFT) revealed that the binding of early hydrogenation product (NH) follows a linear relationship with lattice N over a wide range of close‐packed surfaces. But, the binding of NH2 and NH3 are more sensitive to the geometric and electronic structures. Further, the chemical bonding can be quantitatively characterized with the covalency derived from Crystal Orbital Hamiltonian Population (COHP). In the Eley Rideal‐Mars van Krevelan pathway, the overall NH3 formation free energy (ΔGNH3) and lattice N diffusion barrier (Ea) are the respective thermodynamic and kinetic determining factors. Aided by a rate‐determining step (RDS) model, Mn4N modified with Fe, Co, Ni single‐atom dopants all show enhanced rates for NH3 formation. [ABSTRACT FROM AUTHOR]