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Catalytic N−H bond activation and breaking by well‐defined molecular complexes or their heterogeneous analogues is considered to be a challenge in chemical science. Metal(0) nanoparticles catalytically decompose NH3; they are, however, ill defined and contain a range of contiguous metal sites with varying coordination numbers and catalytic properties. So far, no well‐defined/molecular Mn+‐containing materials have been demonstrated to break strong N−H bonds catalytically, especially in NH3, the molecule with the strongest N−H bonds. Recently, noncatalytic activation of NH3 with the liberation of molecular H2 on an organometallic molybdenum complex was demonstrated. Herein, we show the catalytic activation and breaking of N−H bonds on a singly dispersed, well‐defined, and highly thermally resistant (even under reducing environments) CoII1O4 site of a heterogeneous catalyst for organic (ethylamine) and inorganic (NH3, with the formation of N2 and H2) molecules. The single‐site material serves as a viable precursor to ultrasmall (2.7 nm and less) silica‐supported cobalt nanoparticles; thus, we directly compare the activity of isolated cationic cobalt sites with small cobalt nanoparticles. Density functional theory (DFT) calculations suggest a unique mechanism involving breaking of the N−H bonds in NH3 and N−N coupling steps taking place on a Co1O4 site with the formation of N2H4, which then decomposes to H2 and N2H2; N2H2 subsequently decomposes to H2 and N2. In contrast, Co1N4 sites are not catalytically active, which implies that the ligand environment around a single atom of a heterogeneous catalyst largely controls reactivity. This may open a new chapter for the design of well‐defined heterogeneous materials for N−H bond‐activation reactions.

The performance of Pt–Ru catalysts for methanol electrooxidation has been greatly enhanced by replacing the standard carbon XC72 support with oxygen-functionalized multiwalled carbon nanotubes (MWCNTs). Highly dispersed, intimately contacted Pt–Ru nanoparticles were synthesized on MWNT supports by a combination of strong electrostatic adsorption (SEA) and electroless deposition (ED) methods. The catalysts have been characterized by X-ray diffraction (XRD), scanning transmission electron microscopy (STEM), chemisorption, and X-ray photoelectron spectroscopy (XPS) and evaluated by cyclic voltammetry (CV) for the methanol electrooxidation reaction. The results showed that oxygen-functionalized MWCNTs not only influenced the chemical nature and morphology of the surfaces relative to XC72 but also enhanced the electrocatalytic properties of the resulting Pt and Pt–Ru electrocatalysts. STEM images revealed homogeneous dispersion of uniformly sized nanoparticles (NPs) for the two types of functionalized MWCNTs with relatively high particle density and no notable aggregation. The results also showed that the activities of Pt–Ru on functionalized MWCNT catalysts prepared by SEA and ED for methanol oxidation were much higher than those for commercial catalysts. The activities of −OH- and −COOH-terminated Pt–Ru/MWCNT-OH and Pt–Ru/MWCNT-COOH catalysts for methanol oxidation were up to 7 times higher than that for commercial Pt/XC72 and up to 4 times higher than that for a commercial Pt–Ru/XC72 catalyst with a 1:1 = Pt/Ru bulk atomic ratio.