Sulfur‐33 Isotope Tracing of the Hydrodesulfurization Process: Insights into the Reaction Mechanism, Catalyst Characterization and Improvement

Abstract

The novel approach based on S isotope tracing is proposed for the elucidation of hydrodesulfurization (HDS) mechanisms and characterization of molybdenum sulfide catalysts. The technique involves sulfidation of the catalyst with S-isotope-labeled dihydrogen sulfide, followed by monitoring the fate of the S isotope in the course of the hydrodesulfurization reaction by online mass spectrometry and characterization of the catalyst after the reaction by temperature-programmed oxidation with mass spectrometry (TPO-MS). The results point to different pathways of thiophene transformation over Co or Ni-promoted and unpromoted molybdenum sulfide catalysts, provide information on the role of promoter and give a key for the design of new efficient HDS catalysts.

Methane-Assisted Catalytic Desulfurization in an Environmentally Benign Way

“…2(f), the ratios of m/z intensities 78/76 (0.049) and 80/78 (0.042) for CS 2 in entry 1-S conform well with natural sulfur isotope abundance ( 34 S: 32 S=0.043). However, it is clearly seen that the intensities of m/z at 78 and 80 (correspond to C 32 S 34 S and C 34 S 2 ) increase in entry 1-34S dramatically, indicating the incorporation of S atoms from catalyst in the nal CS 2 product, which can be attributed to the sulfur exchange between 32 S captured from DBT and 34 S initially present in the isotopelabeled catalyst. This sulfur exchange is also reported to be critical for the HDS process in previous studies 33,34 .…”

“…Control experiments prove that the presence of methane, MDS1 and MAC1 are all requisite for this ground-breaking desulfurization route. 13 C isotope labeling experiments suggest the participation of activated methane in the reaction, while 34 S isotope experiments indicate that the sulfur atom in DBT gets adsorbed and interchanged with sulfur vacancies in MDS1, triggering the subsequent reactions. Characterization of catalysts and products, extra con rmation experiments and DFT calculations are further performed and a validated reaction mechanism is proposed.…”

Oxygen-implanted MoS2 nanosheets promoting quinoline synthesis from nitroarenes and aliphatic alcohols via an integrated oxidation transfer hydrogenation–cyclization mechanism

“…Nowadays, the ever-growing stringent environmental legislation is calling for green synthetic methods for the synthesis of fine chemicals, which use efficient catalysts and less harmful solvents or additives. 1 Molybdenum disulfide (MoS 2 ), as a versatile and inexpensive 2D-layer material, is one of the most widely used catalysts originally used for petroleum hydrorefining 2 and then for biomass hydrogenolysis, 3 CO/CO 2 hydrogenation to alcohols, 4,5 and photonic or electronic energy transformation to produce H 2 , 6 CO, 7 CH 3 OH, 8 and NH 3 . 9 However, only a few reaction types, mainly still focusing on hydrogenation, are known for using MoS 2 catalysts in fine chemical synthesis.…”

One-Pot Catalytic Cleavage of C═S Double Bonds by Pd Catalysts at Room Temperature

“…Catalytic activation of carbon sulfur bond is important due to its wide applications in chemical, − energy, and environmental industry. , Hydrodesulfurization (HDS), the conversion of organic sulfur compounds to hydrogen sulfide and hydrocarbons by catalytic technologies, is one of the most important steps in petroleum refining industry, since fossil fuel usually contain organic sulfur impurities. , Furthermore, conversion of hazardous sulfur compounds to harmless chemicals is critical for environmental protection. In general, industrial-scale sulfur removal is carried out through heterogeneous catalysis, , while the mechanisms are still under investigation. , Thus, many efforts have been dedicated to the carbon–sulfur bond activation with transition metal complexes to probe the mechanism for developing highly efficient industrial catalysts. , Different transition metals have been employed to mediate the C–S bond activation, including palladium, − platinum, , rhodium, − iridium, , copper, , nickel, , iron, , cobalt, , ruthenium, , tungsten, and niobium, , among others.…”

“…In general, industrial-scale sulfur removal is carried out through heterogeneous catalysis, 8,9 while the mechanisms are still under investigation. 10,11 Thus, many efforts have been dedicated to the carbon−sulfur bond activation with transition metal complexes to probe the mechanism for developing highly efficient industrial catalysts. 12,13 Different transition metals have been employed to mediate the C−S bond activation, including palladium, 14−16 platinum, 17,18 rhodium, 19−22 iridium, 23,24 copper, 25,26 nickel, 27,28 iron, 18,29 cobalt, 30,31 ruthenium, 32,33 tungsten, 34 and niobium, 35,36 among others.…”