Nanocarbon-supported Pt nanoparticles (NPs) were prepared and tested for the propane dehydrogenation reaction (PDH). The nanocarbon support is composed of a nanodiamond core and a defective, ultrathin graphene nanoshell (ND@G). The Pt/ND@G catalyst experienced slight deactivation during the 100 h PDH test, while the Pt/Al 2 O 3 catalyst showed severe deactivation after the 20 h PDH test. Pt NPs exhibited superior sintering resistance versus that of the ND@G support. This particular support structure of ND@G allows electrons on the defects to transfer to the Pt NPs, leading to a strong metal−support interaction, which significantly prevents Pt NP sintering and promotes the desorption of electron-rich propylene. This electron transfer mechanism was also confirmed by a CO catalytic oxidation test.

Nanocarbon materials are promising catalysts of oxidative dehydrogenation (ODH) of alkanes, but improving the alkene selectivity remains a challenge. A deep understanding and thorough identification of oxygen species on nanocarbons are strongly required for approaches to nanocarbon modification. Successful application of iodometric titration in quantitative determination of the amount of electrophilic oxygen on the surface of carbon nanotubes has been performed in this work. Electrophilic oxygen species have been identified as the main culprits for deep oxidation of ODH of n-butane via a clear correlation between the amount of electrophilic oxygen and combustion reaction rate. By chemical reduction and annealing in nitrogen, the alkene selectivity is significantly improved. Phenol groups are found to play an essential role in improving alkene selectivity. The study reveals that higher alkene selectivity can be achieved by both eliminating deep oxidation active sites and facilitating the formation of phenol and carbonyl groups.

Graphene oxide with different degrees of oxidation was prepared and selected as a model compound of lignite to study quantitatively, using both experiment and theoretical calculation methods, the effect on water-holding capacity of oxygen-containing functional groups. The experimental results showed that graphite can be oxidized, and forms epoxy groups most easily, followed by hydroxyl and carboxyl groups. The prepared graphene oxide forms a membrane-state as a single layer structure, with an irregular surface. The water-holding capacity of lignite increased with the content of oxygen-containing functional groups. The influence on the configuration of water molecule clusters and binding energy of water molecules of different oxygen-containing functional groups was calculated by density functional theory. The calculation results indicated that the configuration of water molecule clusters was totally changed by oxygen-containing functional groups. The order of binding energy produced by oxygen-containing functional groups and water molecules was as follows: carboxyl > edge phenol hydroxyl >epoxy group. Finally, it can be concluded that the potential to form more hydrogen bonds is the key factor influencing the interaction energy between model compounds and water molecules.

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