Effect of Organic Additives on the Structure and Hydrotreating Activity of a CoMoS/Multiwalled Carbon Nanotube Catalyst

Abstract

A comparative study of the effect of citric acid (CA), nitrilotriacetic acid (NTA), and diethylene glycol (DEG) used for the preparation of impregnation solution on the properties and catalytic performance of CoMoS/multiwalled carbon nanotube (MWCNT) hydrotreating catalyst was carried out. For a deeper understanding of the role of organic additives during CoMoS catalyst preparation, thermal analysis, nitrogen physisorption, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy were applied. It was shown that the use of various additives resulted in the formation of CoMoS/MWCNT catalysts with a similar morphology of sulfide particles and similar textural characteristics. However, depending on the type of the additive used, the catalysts exhibited different activities in hydrodesulfurization and hydrodenitrogenation, which changed in the following order: CoMoS–CA > CoMoS–NTA > CoMoS–DEG. CA was found to be the most effective organic additive to the impregnation solution that results in a significant improvement in the activity of the CoMoS catalyst in dibenzothiophene and quinoline conversion as compared to NTA and DEG.

Sorbitol Derived Carbon Coated Alumina Composite as a Promising Support for CoMoS Hydrotreating Catalyst

“…CoMo/Al 2 O 3 and CoMo/C@Al 2 O 3 - x catalysts were synthesized by impregnating the corresponding supports with aqueous solutions of ammonium heptamolybdate tetrahydrate (Sigma-Aldrich), cobalt­(II) carbonate hydrate (Sigma-Aldrich), and citric acid (Reachim Ltd.) as organic complexing agent. The preparation procedure is described in more detail in. , Impregnation solutions were prepared in such a way as to provide 3.2 and 12.0 wt % of Co and Mo in the catalysts, respectively. The prepared catalyst samples were dried for 4 h at 120 °C in a drying chamber with forced convection (air change rate of 80 x/h).…”

Synthesis and characterization of Mo-blue-based sulfided CoMo catalysts for guaiacol HDO

“…Comparative studies (Vatutina et al, 2020) using CoMo formulations over multi-walled carbon nanotubes (MWCNT) found that chelating citric acid was more efficient than diethylene glycol addition in improving DBT HDS and quinoline hydrodenitrogenation. Decreased support-Mo interaction provoked by the later additive was not very effective in promoting activity as impregnated phases were not strongly bonded to MWCNT.…”