Hydrodeoxygenation of p-cresol on MoS2: the effect of adding hexadecyl trimethyl ammonium bromide during the catalyst synthesis

Abstract

This study prepared unsupported MoS 2 catalysts by a one-step hydrothermal method using ammonium heptamolybdate and thiocarbamide as materials. The morphology and microstructure of MoS 2 catalysts were changed by adding different amounts of hexadecyl trimethyl ammonium bromide (CTAB). The resultant catalysts were characterized by X-ray diffraction, nitrogen physisorption and transmission electron microscopy. The surface area and pore volume of MoS 2 increased first and then decreased with the addition amount of CTAB. The structural difference between these catalysts lies in the number of layers in stacks and slab length of MoS 2 structure. The structure-activity correlation was studied by using the hydrodeoxygenation (HDO) of p-cresol as the probe reaction. In the HDO of p-cresol, the end products were toluene, 4-methylcyclohexene and methylcyclohexane, and the possible HDO reaction routes were proposed. The effects of addition of CTAB during the synthesis of MoS 2 and HDO reaction temperature on conversion and products distribution were analyzed. The changes of product distribution were explained based on the Rim-Edge model. The direct deoxygenation (DDO) route occurs on the edge active sites while the hydrogenation-dehydration (HYD) route occurs on brim sites of multistacks MoS 2 particles. Thus, the slab length and slab stacking layers had a great effect on the catalytic activity of MoS 2 and products distribution.Electronic supplementary material The online version of this article (

Vacancy Engineering in Transition Metal Sulfide and Oxide Catalysts for Hydrodeoxygenation of Lignin‐Derived Oxygenates

“…Studies have shown that MoS 2 , which is amorphous and has a short plate length, contains more highly active sulfur vacancies [77] . In the study of the control of slab length, Wang et al [78] . obtained MoS 2 with a shorter slab length and fewer stacked layers by adding an appropriate amount of hexadecyl trimethyl ammonium bromide (CTAB).…”

Role of transition metals on MoS2-based supported catalysts for hydrodeoxygenation (HDO) of propylguaiacol

“…However, the diffraction peaks that correspond to MoS 2 (2θ = 33.4°, 39.5°, 49.5°, 58.6°, and 68.5°) were absent for all studied catalysts. 37 This could be due to the MoS 2 peaks being masked by the alumina peaks, which are in the same region, for instance, 2θ = 33.4° and 39.5°. 37 Another possibility is that the MoS 2 phase was well dispersed on the support and exhibiting low crystallinity.…”

“…37 This could be due to the MoS 2 peaks being masked by the alumina peaks, which are in the same region, for instance, 2θ = 33.4° and 39.5°. 37 Another possibility is that the MoS 2 phase was well dispersed on the support and exhibiting low crystallinity. The metal sulfide phases like NiS, FeS, FeS 2 , and CuS were also not distinguished in the XRD pattern which could be attributed to the relatively low metal loading that is below the XRD detection limit.…”

The critical role of solvent polarity in the preparation of tube-like Co–Mo sulfide catalysts for the hydrodeoxygenation of stearic acid

“…8 In comparison, unsupported catalysts without any support will supply more active components and exhibit better catalytic performance. [9][10][11] The NEBULA TM catalyst family of the Albemarle Catalyst Company is regarded as a representative of unsupported hydroprocessing catalysts, which exhibit at least three times higher HDS activity than traditional g-Al 2 O 3supported CoMo and NiMo catalysts. 12 The unprecedented activity was thought to originate from the abundant metal components, which provide more active sites for the activation of the substrate and H 2 .…”