Nanocarbons have been extensively used as metal-free alternatives to metal catalysts in many oxidative processes owing to their functional groups or defects, which have the activation ability toward oxygen molecules.

Designing heterogeneous metal-free catalysts for hydrogenation is a long-standing challenge in catalysis. Nanodiamond-based carbon materials were prepared that are surface-doped with electron-rich nitrogen and electron-deficient boron. The two heteroatoms are directly bonded to each other to form unquenched Lewis pairs with infinite π-electron donation from the surrounding graphitic structure. Remarkably, these Lewis pairs can split H to form H /H pairs, which subsequently serve as the active species for hydrogenation of different substrates. This unprecedented finding sheds light on the uptake of H across carbon-based materials and suggests that dual Lewis acidity-basicity on the carbon surface may be used to heterogeneously activate a variety of small molecules.

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It is widely believed that low-volatility is a defining characteristic of ionic liquids (ILs). Here we synthesize a series of host-guest nanocomposites containing multiwalled carbon nanotubes (MWCNTs) and ILs using the volatility of ILs under vacuum conditions. The nanocomposites with different IL contents can be easily obtained through simple physical methods. The interactions between IL and MWCNTs are thoroughly investigated. This new nanocomposite can be used both in carbon catalysis and IL catalysis.

The preparation process of industrial Fe-based catalysts for ammonia synthesis involves energy-intense and sophisticated treatments. It is thus highly desirable to develop new catalysts with sufficient catalytic performance within smart and more economic approaches. Herein, γ-Al2O3-supported FeOOH nanosheets are employed for the first time as ammonia synthesis catalysts. To monitor the potential of these new materials, unsupported FeOOH and K-promoted catalysts are additionally investigated for comparison. While no activity is observed from the unsupported catalyst, the activity of γ-Al2O3-supported catalysts shows an inverse relationship with respect to the amount of Fe. Upon correlation of the catalytic performance with the final state of catalysts, the activity is closely related to the particle size of metallic Fe. Higher activity and lower apparent activation energy can be reached for smaller nanoparticles that are likely to contain more step–kink structures serving as active sites. The best catalytic performance is obtained for a K-promoted catalyst which shows an activity about 18 times higher compared to that of the corresponding unpromoted one (at 425 °C). We conclude that, in addition to the nanostructured character of the Fe, the modifications of its electronic and surface structures induced by the K-promoter are responsible for this enhanced activity.