共查询到15条相似文献,搜索用时 31 毫秒
1.
《China Chemical Reporter》2005,(7)
The research to diesel super intensivedesulfurization through oxidative ex-traction undertaken by AcademicianLi Can from CAS Dalian Research In-stitute of Chemistry and Physics hasmade a major breakthrough and ap-plied for two invention patents inChina. A high-effect hydrophilic/ 相似文献
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《China Chemical Reporter》2005,(12)
According to the information released byTsinghua University on March 29,an en-tirely new biological enzyme process thathas simple operation and can effectivelytransform animal and plant grease intobiological diesel has made successful 相似文献
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M. Dhakad Amish G. Joshi S. Rayalu P. Tanwar J. K. Bassin R. Kumar S. Lokhande J. Subrt T. Mitsuhashi Nitin Labhsetwar 《Topics in Catalysis》2009,52(13-20):2070-2075
Alumina supported Co–K–Mo based mixed metal oxide type catalytic materials have been prepared by co-impregnation. These catalysts show excellent activity for carbon as well as diesel soot oxidation, which could be due to the redox properties of Mo and Co as well as to a synergistic effect of molybdenum, cobalt, and K contents. The catalyst containing 5 wt% molybdenum shows a lowering of carbon oxidation by about 190 °C under loose contact conditions as compared to the non-catalyzed reaction, as well as to bare alumina. Characterization studies suggest a composite nature of these materials, while thermal stability investigations confirm the stable nature. The selected catalyst has been studied by XPS, however, it is difficult to conclude which are the important factors contributing to the catalytic activity. It appears to be a synergistic effect of Co, K, and Mo components as these catalysts show much improved activity as compared to the individual components in supported and unsupported forms. 相似文献
4.
Yanyong Liu Kazuhisa Murata Kiyomi Okabe Megumu Inaba Isao Takahara Toshiaki Hanaoka Kinya Sakanishi 《Topics in Catalysis》2009,52(6-7):597-608
Polyoxocation ([AlO4Al12(OH)24(H2O)12]7+ and [Zr4(OH)14(H2O)10]2+)-pillared montmorillonites were prepared by ion exchange, and they were used as solid acid catalysts, in comparison to some other solid acids, for the selective hydrocracking of Fischer–Tropsch waxes to diesel-ranged hydrocarbons. XRD patterns and elemental analyses proved that the polyoxocations were successfully introduced into the interlayer region of the montmorillonites. N2 adsorption–desorption measurement indicated that polyoxocation-pillared montmorillonites have large BET surface areas (>230 m2 g?1), high thermal stability (>673 K), and large pores (comparing to those in zeolites). FT-IR spectra of chemisorbed pyridine indicated that polyoxocation-pillared montmorillonites possess both Lewis and Bronsted acid sites on the solid surface. Temperature-programmed desorption of ammonia indicated that the acidity strength of the polyoxocation-pillared montmorillonites was weaker than those of H–ZSM-5, H–Y, WO3/ZrO2, and Al2O3–SiO2. In the hydrocracking of Fischer–Tropsch (F–T) waxes, the acidity strength of the solid acids in bifunctional catalysts greatly influences the product composition. Pt-promoted H–Y afforded a high yield of gasoline-ranged hydrocarbons (>90%) while Pt-promoted H–ZSM-5 afforded a larger amount of gas products due to its strong solid acid sites. On the other hand, among various catalysts, Pt-modified polyoxocation-pillared montmorillonites afforded the highest yield of diesel-ranged hydrocarbons (>70%) due to the appropriately weak acid strength, high thermal stability, large BET surface area, and large pore size. Pt is necessary for the hydrocracking of F–T waxes because it enables hydrogenation/dehydrogenation. However, a high Pt loading on the catalyst produces more light hydrocarbons due to the stimulation of hydrogenolysis. High hydrogen pressure improved the selectivity for diesel-ranged hydrocarbons but decreased the conversion of F–T waxes due to the suppression of alkane dehydrogenation. The hydrocracking of F–T waxes at a low temperature with a large amount of catalyst for longer reaction time increased the yield of diesel-ranged hydrocarbons. 相似文献
5.
In this study, Euro V diesel fuel, biodiesel, and methanol–biodiesel blends were tested in a 4-cylinder direct-injection diesel engine to investigate the combustion characteristics and particulate emissions of the diesel engine under five engine loads at the maximum torque engine speed of 1800 rpm. Compared with Euro V diesel fuel, biodiesel gives lower and earlier heat release rate. For the blended fuels, the peak heat release rate becomes higher and retarded. With regard to particulate mass concentration, biodiesel generates less than Euro V diesel fuel, while the blended fuels result in significant reduction especially at high engine loads. Compare with Euro V diesel fuel, the total particle number concentration of using biodiesel is always higher while the geometric mean diameter (GMD) of the particles is lower. With the blended fuel, the total number concentration and GMD decrease in comparison with pure biodiesel. Further analysis shows that the difference between the total number concentration of biodiesel and Euro V diesel fuel is in particles smaller than 50 nm rather than in the larger particles. The use of methanol–biodiesel blends, compared with biodiesel, could reduce the number concentration of all sizes. A comparison between the particulate mass emission and total particulate number concentration with the mass of fuel burned in the diffusion mode show that they are strongly related to each other, even for the blended fuel. 相似文献
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Tanja Kolli Mika Huuhtanen Tomi Kanerva Minnamari Vippola Kauko Kallinen Toni Kinnunen Toivo Lepist? Jouko Lahtinen Riitta L. Keiski 《Topics in Catalysis》2011,54(16-18):1185-1189
Sulphur, sulphur-water, and water pretreatments were done to find out the effect of these compounds on a diesel oxidation Pd/??-zeolite catalyst and ??-zeolite washcoat. After pretreatments, the samples were analysed by BET, XRF, TEM-SEM, and XPS. In addition, the activity of fresh and pretreated Pd/??-zeolite catalysts was studied utilizing the by Gasmet FT-IR in production gas analysis. Sulphur compounds (SO2 or ?SO4) were found to have a deactivating effect on the activity of the studied Pd/??-zeolite catalyst. 相似文献
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A series of naometric perovskite catalysts LaCo1?x Pd x O3 (x = 0, 0.01, 0.03) were prepared via a solution combustion synthesis route using metal nitrates as oxidizers and urea as fuel. It is essential to add a certain amount of ammonia aqueous solution to Pd2+ ions solution in the catalyst preparation process. Homogeneous nanoparticles LaCo1?x Pd x O3 catalysts with the sizes in the range of 68–122 nm were obtained and characterized by using of XRD, BET, H2-TPR, XPS, SEM and TEM. Pd was successfully introduced into the LaCoO3 perovskite lattices. Further information was obtained by using XPS upon the LaCo0.97Pd0.03O3 (with NH4OH) sample after H2-TPR. The results revealed that surface Pd was reduced to the metallic state at the end of the first step in the H2-TPR experiment, and some surface Co could be reduced to metallic Co simultaneously. The catalytic properties were investigated for simultaneous NO x -soot removal reaction. The performance of LaCo1?x Pd x O3 catalysts were greatly improved by the partial substitution of Pd. The maximum NO conversion into N2 and the ignition temperature of soot are 32.8% and 265 °C, respectively. 相似文献
8.
Motoi Sasaki Kunio Suzuki Asima Sultana Masaaki Haneda Hideaki Hamada 《Topics in Catalysis》2013,56(1-8):205-209
The activity of Pt catalysts supported on Al2O3 modified with various acid–base additives has been investigated for oxidation of NO to NO2. Although Pt dispersion was changed by the additives, there was no clear effect of Pt dispersion on the catalytic activity. The measurement of solid acid–base properties of the modified Pt/Al2O3 indicated that the NO oxidation activity increased by the increase of surface density of strong acid sites and decreased by the increase of basic sites. It was suggested that platinum on the acidic supports keeps its highly active metallic state for NO oxidation, while the formation of nitrate/nitrite on the basic supports inhibits the reaction on the Pt surface. 相似文献
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A series of the La2Ni1?x Cu x O4 (0 ≤ x ≤ 1.0) perovskite-like complex oxide catalysts, prepared and characterized by XRD, H2-TPR, O2-TPD and XPS, and catalytic activity tests, proved to be effective in the simultaneous removal of NOx and soot. The results indicated that the catalysts show the single orthorhombic K2NiF4-like phase. The doping of Cu led to the increase of orthorhombic distortion and the decrease of capability to accommodate non-stoichiometric oxygen, as well as the increase of the reducibility of lattice oxygen, resulting in improving catalytic activities. The La2Ni0.4Cu0.6O4 catalyst showed the highest activity. The maximum conversion of nitrogen oxide to molecular nitrogen was 15.6% and the ignition temperature decreased from 440 to 246 °C, as compared with the uncatalyzed soot combustion reaction. 相似文献
11.
N. Mota M. C. Álvarez-Galván J. A. Villoria F. Rosa J. L. G. Fierro R. M. Navarro 《Topics in Catalysis》2009,52(13-20):1995-2000
Catalysts derived from perovskite type oxides LaCo1?x M x O3 (M = Ru or Fe, x = 0.2) synthesized by a modified citrate sol–gel method were tested in the oxidative reforming of diesel for hydrogen production. Physicochemical characterization of the samples revealed differences in the surface area, crystalline size, reducibility and relative distribution of the cobalt active phase on the surface of catalyst. These properties have important implications in the catalytic behaviour of the samples in the oxidative reforming of diesel. The increase in reducibility and metal exposition implies higher reforming activity as it was observed for the catalyst derived from LaCo0.8Ru0.2O3. 相似文献
12.
Antonio Grossale Isabella Nova Enrico Tronconi Daniel Chatterjee Michel Weibel 《Topics in Catalysis》2009,52(13-20):1837-1841
The activity and the mechanism of the main reactions in the NO/NO2–NH3 SCR reacting system were comparatively investigated over a Fe- and a Cu-promoted commercial zeolite catalyst for the aftertreatment of Diesel exhausts. A dynamic micro-kinetic model in close agreement with all the details of the SCR catalytic chemistry was also developed. 相似文献
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Hong Wang Zhen Zhao Peng Liang Chunming Xu Aijun Duan Guiyuan Jiang Jie Xu Jian Liu 《Catalysis Letters》2008,124(1-2):91-99
The nanometric La1?x K x CoO3 (x = 0–0.30) perovskite-type oxides were prepared by a citric acid-ligated method. The catalysts were characterized by means of XRD, IR, BET, XPS and SEM. The catalytic activity for the simultaneous removal of soot and nitrogen oxides was evaluated by a technique of the temperature-programmed oxidation reaction. In the LaCoO3 catalyst, the partial substitution of La3+ at A-site by alkali metal K+ enhanced the catalytic activity for the oxidation of soot particle and reduction of NO x . The La0.70K0.30CoO3 oxides are good candidate catalysts for the simultaneous removal of soot particle and NO x . The combustion temperatures for soot particles over the La0.70K0.30CoO3 catalyst are in the range from 289 to 461 °C, the selectivity of CO2 is 98.4% and the conversion of NO to N2 is 34.6% under loose contact conditions. The possible reasons that can lead to the activity enhancement for the K-substitution samples compared to the unsubstituted sample (LaCoO3) were given. The particle size has a large effect on its catalytic performance for the simultaneous removal of diesel soot and nitrogen oxides. 相似文献
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