Perspectives on Advances in the Catalytic Desulfurization and Denitrogenation of Transportation Fuel Oils Using Graphitic Carbon Nitride and Boron Nitride

Expulsion of sulfur-containing compounds as well as nitrogen-containing compounds present in fuel oils is critical because it can cause numerous environmental problems and catalyst deactivation. Because of the limitations of the other catalysts and adsorbents used for desulfurization, a new type of carbon material, i.e., graphitic carbon nitride (g-C3N4), has emerged. It is similar in morphology to graphene having a two-dimensional structure and possessing a band gap of 2.7 eV and is an attractive catalyst attributed to its intriguing characteristics like high intrinsic photoresponsiveness and photoabsorption, semiconductive properties, and better stability. An ample amount of literature has been documented on g-C3N4 applied for the desulfurization and denitrogenation of fuel oils. Due to the analogy of boron with carbon materials, boron nitrides (BN) are also important. In materials chemistry, hexagonal BN (h-BN), often termed as "white graphene", among the different phases of BN, is highly regarded due to adaptation of diverse morphologies such as nanotubes and nanosheets. BN has been recommended as an emerging and efficacious 2D material in catalysis because it possesses oxidative resistance, chemically inertness, a sp2-bonded layered structure, wide band gap, and higher thermal stability and conductivity. This review systematically encompasses the important reports documented on the applications of g-C3N4 and BNs in fuel oil processing including the synthesis, various properties, and fascinating experimental findings. Later on, key suggestions are put forward for future research directions and new technologies applying g-C3N4 and BN for the processing of transportation fuels. This review could act as a concentrated platform, as a quick access source and great degree of convenience, giving time effective routes for researchers to reported results and designs of novel and efficacious catalysts for the commercialization of desulfurization and denitrogenation technologies.