Novel metal-free N-doped bio-graphenes and their MoO3 bifunctional catalysts for ultra-deep oxidative desulfurization of heavy fuel

We developed here a green procedure for the synthesis of novel N-doped bio-graphenes from Arabic gum as a natural source by using different N-dopants (urea, hexamethyleneteramine, and ethylenediamine) and Gelatin as a carbon source containing N species. The effect of these dopants on the type of nitrogen species, nitrogen contents, and surface structure of graphene catalysts was investigated on their catalytic properties for oxidative removal of sulfur compounds in fuel oil. All of doped graphenes show the pyridinic and pyrrolic nitrogen species, while the graphene doped with hexamethylenetetramine shows the highest amount of nitrogen with some content of amine group as well as pyridinc-N and pyrrolic-N. This N-doped graphene indicates the highest catalytic activity due to the type of nitrogen species, higher nitrogen content, and higher surface area. The resulting immobilized catalysts with MoO3 also show the similar trend in catalytic activities. Nitrogen doping increase the electron density of peroxo groups by donating electrons to Mo-centers which enhance the catalytic activity by decreasing the oxidation barrier.

Automated summary

A green procedure was developed to synthesize novel N-doped bio-graphenes from Arabic gum using different N-dopants and Gelatin as carbon source. The nitrogen-doped graphenes exhibited enhanced catalytic activity for oxidative removal of sulfur compounds in fuel oil, with the graphene doped with hexamethylenetetramine showing the highest catalytic activity due to its nitrogen species, nitrogen content, and surface area.