新型氧化铝基制硫催化剂的研制

介绍了LS-02新型氧化铝制硫催化剂的研制、表征及活性评价。该催化剂以氧化铝为主要原料,采用转动成型工艺制备。该催化剂较LS-300催化剂具有更高的比表面积、更大的孔体积、更合理的孔分布及更高的克劳斯活性和水解活性,综合性能达到国外同类催化剂水平。

LS-941 H_2S选择性氧化制硫催化剂的研制

报道LS - 94 1H2 S选择性氧化催化剂的实验室研制及活性评价结果。该催化剂以惰性氧化铝为载体 ,以Fe/Cr为活性组分并添加专利助剂制备而成 ,经过实验室 10 0 0h的活性评价 ,硫收率一直保持在 90 %以上 。

LS—931硫磺回收催化剂的工业应用

本文根据我厂首次使用LS－931型制硫催化剂前后的情况的对比，认为在相同的工艺条件下，使用LS－931型制硫催化剂，其使用活性，稳定性以及抗干扰能力均优于同类Al2O3型制硫催化剂，具有较好的经济效益和环保效益。

LS-02催化剂的工业放大生产及应用

介绍LS-02催化剂的工业放大生产。结果表明,LS-02催化剂在物化性质和催化活性上达到国外同类催化剂水平。在80kt/a硫磺回收装置上进行了LS-02催化剂工业应用试验,与换剂前相比较,一转入口温度降低约15℃,床层温升升高近10℃,单程总硫转化率提高0.5～1.0个百分点。

Hydrogenation Conversion of Phenanthrene over Dispersed Mo-based Catalysts

With oil-soluble molybdenum compound and sublimed sulfur serving as raw materials, two dispersed Mo-based catalysts were prepared, characterized and then applied to the hydrogenation conversion of phenanthrene. The test results showed that under the conditions specified by this study, the catalyst prepared in a higher sulfiding atmosphere was more catalytically active due to its higher content of MoS2 and stronger intrinsic catalytic activity of MoS2 unit, which demonstrated that the sulfiding atmosphere for the preparation of catalysts not only could influence the yield of MoS2 but also the structure of MoS2.The analysis on the selectivity of octahydrophenanthrene isomers revealed that the catalyst prepared in a lower sulfiding atmosphere had a relatively higher catalytic selectivity to the hydrogenation of outer aromatic ring and the structure of catalysts could be modified under the specific reaction conditions. Moreover, the selectivity between the isomers of as-octahydrophenanthrene at different reaction time and temperature was analyzed and, based on the results, a hydrogenation mechanism over dispersed Mo-based catalysts was suggested, with monatomic hydrogen transfer and catalytic surface desorption of the half-addition intermediates functioning as the key points. In addition, it is concluded that the catalyst prepared in a lower sulfiding atmosphere was more capable of adsorption than the other one.

Preparation of chemical manganese dioxide from manganese sulfate

Chemical Manganese Dioxide （CMD） was prepared by an alkali-oxidation method. There are several virtues to this environmental friendly and clean process, including the nontoxic and harmless reagents and products, easy operations, no pollutants, easily obtained raw materials and moderate reaction conditions. The synthesized manganese dioxide was characterized by XRD and SEM. The particles were small, consisting primarily of α-MnO2 and γ-MnO2. Experimental results showed that the optimum conditions were： MnSOa.H20 to NaOH ratio, 1.0：2.4; catalyst concentration （catalyst TF-2）, 6% of the MnSO4; initial solution pH, 11; reaction time and temperature, 20 min and 80 ℃; air flow, 0.20 m3/h; and, agitation rate, 700 r/rain. The conversion of MnSO4 can exceed 80% under these optimum conditions.

Preparation of Cu-BiVO_4 and Its Photocatalytic Properties for Desulfurization of Model Oil

A photocatalyst Cu-BiVO4 was synthesized by the hydrothermal method and was characterized by XRD, UV-vis DRS, and N2 adsorption-desorption measurement. The catalytic activity of the Cu-BiVO4 samples was studied on desulfurization of thiophene dissolved in n-octane, which was used as a model light oil, via photocatalytic oxidation reaction under illumination by visible light. The catalyst characterization results indicated that the loading of Cu on the catalyst did not change the crystal phase of BiVO4, and the crystallinity of the Cu-BiVO4 sample was found to be better at pH=7. The Cu-BiVO4 samples presented a significant bathochromic shift of the absorption band in the visible region, and the absorption intensity increased for the composite catalyst. The desulfurization experiments showed that the Cu-BiVO4 sample prepared at a pH value of 7 had a better catalytic activity. Under proper operating conditions, the desulfurization rate of the model compound achieved by Cu-BiVO4 sample prepared at pH=7 could reach as high as 90%.

Effect of Operation Variables on Hydrodenitrogenation and Hydrodesulfurization over NiMo/Al_2O_3 Catalysts

Using the JQ-II high pressure hydrogenation micro-reactor unit, the reactivity of Athabasca bitumen derived heavy gas oil was studied over commercial and homemade hydrotreating catalysts. The effects of catalyst preparation variables and the influences of operation conditions, such as pressure, temperature, hydrogen/oil ratio and space velocity were also examined. It was shown that the optimal concentrations of the active components were 5% of NiO, 20% of MoO3 and 3.5% of phosphorus (by mass), and the suitable operation conditions were determined experimentally.

Design of the Metal Precursors Molecular Structures in Impregnating Solutions for Preparation of Efficient Ni Mo/Al_2O_3 Hydrodesulfurization Catalysts

The molecular structures of metal precursors in the impregnating solution were designed so as to prepare efficient Ni Mo/Al_2O_3 hydrodesulfurization(HDS) catalysts. At first, five typical impregnating solutions were designed; the existing metal precursors, such as [Mo4(citrate)2O11]^(4-)-like, [P2Mo18O62]^(6-)-like and [P2Mo5O23]^(6-)-like species in the solutions were confirmed by laser Raman spectroscopy(LRS). The UV-Vis spectra results indicated that the solutions containing both phosphoric acid and citric acid could change the existing form of nickel species. Five corresponding Ni Mo/Al_2O_3 catalysts were prepared by the incipient wetness impregnation method. The LRS analysis results of dried catalysts showed that the above metal precursors could be partly retained on alumina support after impregnation and drying, although the interface reaction between different metal precursors and alumina support unavoidably took place. Then the catalysts were sulfided and characterized by N2 physisorption, TEM and XPS analyses. The results showed that different metal precursors in impregnating solution could mainly result in the difference in both the morphology of(Ni)Mo S2 slabs and the promoting effect of Ni species. The catalyst prepared mainly with [P2Mo5O23]^(6-)-like species used as precursors exhibited worse dispersion of(Ni)Mo S2 slabs and lower ratio of Ni–Mo–S active phases than the one with [Mo4(citrate)2O11]^(4-)-like species. Promisingly, the catalyst prepared with co-existing [Mo4(citrate)2O11]^(4-)-like, [P2Mo18O62]^(6-)-like and [P2Mo5O23]^(6-)-like species showed better hydrodesulfurization activity for 4,6-DMDBT thanks to its more well-dispersed Ni–Mo–S active phases.

Effect of Sulfurization Temperature on Thioetherification Performance of Mo-Ni/Al_2O_3 Catalyst

The Mo modified Ni/Al_2O_3 catalysts were prepared and sulfided at different temperatures, and their catalytic activity for thioetherification of mercaptans and olefins(or dienes), hydrogenation of dienes and olefins in the thioetherification process using fluidized catalytic cracking(FCC) naphtha as the feedstock was investigated. In order to disclose the correlation between the physicochemical characteristics of catalysts and their catalytic activity, the surface structures and properties of the catalysts sulfided at different temperatures were characterized by the high resolution transmission electronic microscopy(HRTEM), X-ray photoelectron spectroscopy(XPS) and H2-temperature programmed reduction(H_2-TPR) technique. The results showed that an increase of sulfurization temperature not only could promote the sulfurization degree of active metals on the catalysts, but also could adjust the micro-morphology of active species. These changes could improve the catalytic performance of thioetherification, and hydrogenation of dienes and olefins. However, an excess sulfurization temperature was more easily to upgrade the ability of the catalyst for hydrogenation of olefins, which could lead to a decrease of the octane number of the product. It was also showed that a moderate sulfurization temperature not only could improve the catalytic performance of thioetherification and hydrogenation of dienes but also could control hydrogenation of olefins.

Nanostructured CdS for efficient photocatalytic H2 evolution: A review

Cadmium sulfide(Cd S)-based photocatalysts have attracted extensive attention owing to their strong visible light absorption,suitable band energy levels,and excellent electronic charge transportation properties.This review focuses on the recent progress related to the design,modification,and construction of Cd S-based photocatalysts with excellent photocatalytic H2 evolution performances.First,the basic concepts and mechanisms of photocatalytic H2 evolution are briefly introduced.Thereafter,the fundamental properties,important advancements,and bottlenecks of Cd S in photocatalytic H2 generation are presented in detail to provide an overview of the potential of this material.Subsequently,various modification strategies adopted for Cd S-based photocatalysts to yield solar H2 are discussed,among which the effective approaches aim at generating more charge carriers,promoting efficient charge separation,boosting interfacial charge transfer,accelerating charge utilization,and suppressing charge-induced self-photocorrosion.The critical factors governing the performance of the photocatalyst and the feasibility of each modification strategy toward shaping future research directions are comprehensively discussed with examples.Finally,the prospects and challenges encountered in developing nanostructured Cd S and Cd S-based nanocomposites in photocatalytic H2 evolution are presented.