Effects of composition and morphology of active phase of CoMo/Al2O3 catalysts prepared using Co2Mo10–heteropolyacid and chelating agents on their catalytic properties in HDS and HYD reactions

Preparation of Ni-Mo 2 C/carbon catalysts and their stability in the HDS of dibenzothiophene

“…However, CHNS and XPS analysis both showed that S was present on the surface of the used catalysts. Note that the measured d-spacing from the TEM is ~0.63 nm (Figure 6), indicating the formation of MoS2 species on the used NiMo2C/AC catalysts [36]. A similar observation was reported by Zhang et al [37] on a used…”

Improvement of HDS catalysts through the modification of the oxidic precursor with 1,5-pentanediol: Gas phase sulfidation and thiophene conversion

“…Among them the use of Keggin or Anderson based heteropolyanions was proposed several years ago to prepare impregnating solutions instead of the classical ammonium heptamolybdate precursor [2,3]. Improvements have also been obtained through the addition of organic agents to the impregnating solution prepared with [4,5] or without [6] heteropolyanions. More recently the modification of dried or calcined oxidic precursors by organic molecules was shown to improve HDS catalytic performances [7e10].…”

“…Whatever the approach, various organic agents that have been used can be divided in two families: the chelating agents allowing complexation with metallic ions and the non-chelating agents. Among the chelating molecules, EDTA (ethylenediaminetetraacetic acid) [11], En (ethylenediamine) [12,13], CyDTA (cyclohexanediaminetetraacetic acid), NTA (nitrilotriacetic acid), TA (tartaric acid) [5] or saccharose [14] were considered. In our laboratory TGA (thioglycolic acid) [7,8], also described as a sulfiding agent [15], was used to impregnate a commercial CoMo/Al 2 O 3 oxidic precursor.…”

Morphology tuning of CoMo catalysts: Effect of La and Fe as an additive

“…It shows that the spectra contained three Mo 3d doublets and the peak of S 2s about 225.9 eV [12]. According to literature [13], the binding energies at 232.3 eV and 235. 4 The representative HRTEM micrographs of three catalysts are provided in Fig.3.…”