Molybdenum Dioxide Nanoparticles Anchored on Nitrogen-Doped Carbon Nanotubes as Oxidative Desulfurization Catalysts: Role of Electron Transfer in Activity and Reusability

Ni modified MoO3 (Ni-MoO3) had been synthesized by a facile one-step hydrothermal technique and was used for oxidative desulfurization (ODS) of dibenzothiophene (DBT) in the decalin/acetonitrile biphasic system with H2O2 as oxidant, the effect of different operating conditions was investigated. Under the optimal reaction condition, Ni-MoO3 catalyst showed excellent ODS performance toward DBT, the highest sulfur removal efficiency can be up to 99.8% and sulfur content was wiped out from 5000 to 10 ppm, which is more effective than the recent reported MoO3-based catalysts. The reaction kinetics obeyed the pseudo-first-order equation with an apparent rate constant of 0.076 min−1, which is twice that of pure MoO3 (0.035 min−1). The ODS mechanism of DBT with Ni-MoO3 was explored by combining radical scavenger, FT-IR experiments and theoretical analysis, proving that surface oxygen vacancies and Lewis acid sites play important roles in the high-efficiency ODS reaction with Ni-MoO3 catalyst.

Highly efficient oxidative desulfurization of dibenzothiophene using Ni modified MoO3 catalyst

Synthesis of NiS–MoO3 nanocomposites and decorated on graphene oxides for heterogeneous photocatalysis, antibacterial and antioxidant activities

An effective process to remove sulfur compounds from fuel has been explored. The tungsten atoms modified MoO3 as active species was used to enhance the desulfurization activities, and MOF materials to provide a stable place. Meanwhile, the successful introduction of magnetic Fe3O4 could lead to an easily separation after the reaction with simple external magnet to achieve the catalyst recycling use and the final catalyst was named as Fe3O4@W-MoO3@MOF. To noted, various W contents in catalyst system showed a different influence on the ODS process and the ultra-deep desulfurization result could be obtained once the 30 % W loading amount was introduced. Under the optimal reaction conditions, DBT could be completely oxidized in 60 min and there is no apparent losing of activity after at least 18 times of recycling. As for the actual diesel, it was demonstrated that an excellent reactivity was also achieved.

Highly effective oxidative desulfurization with magnetic MOF supported W-MoO3 catalyst under oxygen as oxidant

The ceaseless increase of pollution cases due to the tremendous consumption of fossil fuels has steered the world towards an environmental crisis and necessitated urgency to curtail noxious sulfur oxide emissions. Since the world is moving toward green chemistry, a fuel desulfurization process driven by clean technology is of paramount significance in the field of environmental remediation. Among the novel desulfurization techniques, the oxidative desulfurization (ODS) process has been intensively studied and is highlighted as the rising star to effectuate sulfur-free fuels due to its mild reaction conditions and remarkable desulfurization performances in the past decade. This critical review emphasizes the latest advances in thermal catalytic ODS and photocatalytic ODS related to the design and synthesis routes of myriad materials. This encompasses the engineering of metal oxides, ionic liquids, deep eutectic solvents, polyoxometalates, metal-organic frameworks, metal-free materials and their hybrids in the customization of advantageous properties in terms of morphology, topography, composition and electronic states. The essential connection between catalyst characteristics and performances in ODS will be critically discussed along with corresponding reaction mechanisms to provide thorough insight for shaping future research directions. The impacts of oxidant type, solvent type, temperature and other pivotal factors on the effectiveness of ODS are outlined. Finally, a summary of confronted challenges and future outlooks in the journey to ODS application is presented.

A current overview of the oxidative desulfurization of fuels utilizing heat and solar light: from materials design to catalysis for clean energy

Herein, MoO3 nanowires (Fe–MoO3 NWs) along the [110] direction were successfully synthesized in the presence of Fe3+ cations. The Fe–MoO3 NWs present a large specific surface area of 174.7 m2 g−1 and rich surface –OH groups, and the possible formation mechanism of such a structure is due to the adsorption of Fe3+ cations toward non-(110) planes of MoO3 in solution with pH greater than its isoelectric point. The obtained Fe–MoO3 NWs show excellent and highly selective adsorption capacity toward quasi-phenothiazine dyes (methylene blue, toluidine blue, azure I, and acridine orange). The dye removal rate could reach 99% in 3 min, and the maximum adsorption capacity is up to 144.3 mg g−1 and the adsorption is up to 28.86 mg g−1 per minute, which is 11 times greater than that of pure MoO3 and far greater than that of the recently reported MoO3 nanostructures. This excellent selective adsorption performance of Fe–MoO3 NWs was mainly attributed to the enhanced chemical adsorption of quasi-phenothiazine dyes by rich surface –OH groups and Fe species through hydrogen bond and coordination bond adsorption with N and S, respectively, which was confirmed by adsorption isotherms and adsorption kinetics. These results suggest the potential application of Fe–MoO3 NWs in the field of water pollution treatment.

Fe containing MoO3 nanowires grown along the [110] direction and their fast selective adsorption of quasi-phenothiazine dyes

The invention discloses a preparation method of a cation-modified molybdenum oxide or tungsten oxide nanowire with a large specific surface area. The preparation method comprises the following steps of: dissolving inorganic cations and a molybdenum source or tungsten source in deionized water, stirring solution, simultaneously regulating the pH value of the solution to be above an isoelectric point of molybdenum oxide or tungsten oxide by using protonic acid, then transferring into a self-pressure reaction kettle, reacting for 1-30 hours at a constant temperature of 100-240 DEG C after sealing, separating out solid products after the reaction is ended, washing, and drying to obtain the cation-modified molybdenum oxide or tungsten oxide nanowire with the large specific surface area. The cation-modified molybdenum oxide or tungsten oxide nanowire has the characteristics that the diameter is small, the distribution is narrow (3-10nm), the length-diameter ratio is more than 250, the porouseffect is achieved, the specific surface area is not smaller than 200m /g, the degree of crystallinity is lower and the surface hydroxyl groups are rich and the like.

Ying Cao

Papers

Highly efficient oxidative desulfurization of dibenzothiophene using Ni modified MoO3 catalyst

Fe containing MoO3 nanowires grown along the [110] direction and their fast selective adsorption of quasi-phenothiazine dyes

Preparation method of cation-modified molybdenum oxide or tungsten oxide nanowire with large specific surface area