Functionalization and Characterization of Carbon Nanohorns (CNHs) for Hydrotreating of Gas Oils

Improvement in the functionality of carbon nanohorns (CNHs), a novel carbon nanomaterial, for hydrotreating applications is investigated in the present work. The current work was carried out by using pristine CNHs synthesized by the submerged arc in liquid nitrogen and their corresponding physicochemical properties were investigated. The surface area, pore diameter and pore volume of the pristine CNHs are 129 m(2)/g, 23.1 nm, and 0.64 cm(3)/g respectively. Functionalizing the CNHs with 30 wt% HNO3 under reflux for 15 min to 4 h at 110 A degrees C modified the physical and chemical properties. 30 min functionalization duration was found to be the best and a co-impregnation method was used to load Ni (2.5 wt%) and Mo (13 wt%) onto the support. Techniques used to thoroughly characterize the properties of pristine CNHs, functionalized CNHs and NiMo/CNHs catalyst include: Brauner-Emmett-Teller (BET), Fourier Transform Infrared (FTIR) and Raman Spectroscopy. Type II isotherm and mesoporous pore diameter was observed for CNHs in it's pristine, functionalized or catalyst form. An increase in surface area of over 500 m(2)/g was also attained under optimum functionalized conditions. The pore volume of acid treated CNH samples for hydrotreating increased by similar to 10 % as compared to the pore volume of the pristine CNHs. FTIR results revealed the presence of carboxylic acid (-COOH) groups on the functionalized CNHs and I (D)/I (G) ratios from Raman spectroscopy was used to assess the increase in defects (nanowindow) on functionalized CNHs. The enhanced properties of functionalized and catalyst-supported CNHs offers prospect for hydrotreating gas oils.