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71.
High surface area carbon-supported platinum-based catalysts, Pt/C, PtWO
x
/C, PtRu/C and PtRuWO
x
/C, were prepared via a chemical reduction route using single metal precursor salts. The catalyst particles were found to
be in the nanoscale range, and the addition of Ru clearly decreased the particle size. The Ru was found to be partially incorporated
into the face centered cubic lattice of Pt and to form a single Ru catalyst component. X-ray diffraction and X-ray photon
spectroscopy did not provide evidence for electronic interactions between WO
x
and Pt as well as WO
x
and Ru. However, the addition of tungsten to the PtRuWO
x
/C catalyst resulted in a high degree of catalyst particle agglomeration. Both Ru containing catalysts showed significantly
higher activities for the CH3OH oxidation reaction in terms of Pt + Ru mass as well as electroactive Pt + Ru surface area than the Pt/C and PtWO
x
/C catalysts. The addition of tungsten appeared to mainly result in some ‘physical’ modification of the catalytically active
Pt and Ru surface components such as differences in electroactive surface area rather than promotion of the CH3OH oxidation reaction via a true catalytic mechanism. 相似文献
72.
以甲基二氯硅烷和甲醇为原料,采用气-液相反应法合成出甲基二甲氧基硅烷;然后,将甲基二甲氧基硅烷与3,3,3-三氟丙烯在铂催化剂作用下进行硅氢加成反应,得到3,3,3-三氟丙基甲基二甲氧基硅烷。考察了原料配比、填料种类等因素对醇解反应的影响以及铂催化剂的种类、用量、反应温度等对加成反应的影响。结果表明,最优合成条件为:在醇解反应中,甲基二氯硅烷与甲醇的量之比为1∶1·8、醇解温度50℃、甲醇滴加速度2mL/min、N2流量80mL/min,在此条件下,甲基二甲氧基硅烷的收率为86%;在加成反应中,采用自制的铂催化剂,当铂催化剂与甲基二甲氧基硅烷的量之比为3·0×10-4∶1、反应温度为120℃时,3,3,3-三氟丙基甲基二甲氧基硅烷的收率达90%。此法可有效提高3,3,3-三氟丙基甲基二甲氧基硅烷的收率。 相似文献
73.
74.
阐述了合成油的技术、MTG工艺技术数据及我国联醇工业的发展,根据合成油、合成氨、甲醇原料相近的特点,以及合成油、合成氨联产工艺技术开发及工业性试验的结果,分析论证了合成油、合成氨联产的可行性。 相似文献
75.
Several investigations have been carried out on Cu/ZnO catalysts by employing extended Xray absorption fine structure (EXAFS) and Xray photoelectron spectroscopy (XPS). EXAFS investigations of Cu/ZnO catalysts subjected to hydrogen reduction show the presence of Cu1+ species and Cu microclusters. The proportion of Cu1+ depends on the rate of increase of the reduction temperature and on the amount of alumina added. An XPS study of the interaction of CO with model Cu/ZnO catalysts prepared in situ in the electron spectrometer shows the formation of CO2
-, CO3
2- and C2O4
2- species, their proportion relative to CO increasing with the Cu1+/Cu0 ratio. A study of the interaction of CH3OH with Cu clusters deposited on ZnO films reveals reversible molecular adsorption and the formation of CH3O on clean Cu clusters. If the Cu clusters are pretreated with oxygen, however, both CH3O and HCOO- species are produced. Model Cu/ZnO catalyst surfaces containing both Cu1+ and Cu0 species show interesting oxidation properties. On a Cu0-rich catalyst surface, only the CH3O species is formed on interaction with CH3OH. On a Cu1+rich surface, the HCOO- ion is the predominant species. 相似文献
76.
77.
C307型中低压甲醇合成催化剂的工业应用 总被引:9,自引:0,他引:9
简述了德士古水煤浆气化工艺流程及设备,介绍了C307型甲醇合成催化剂的物化性能及装填情况,主要介绍了该催化剂在兖矿鲁南化肥厂的前期使用情况,并对使用结果进行了评价,C307甲醇合成催化剂低温活性好、选择性好、低还原收缩率、副产物少,经济效益显著。 相似文献
78.
综述甲醇工业技术现状,分析目前国内外甲醇工业的生产发展情况,未来3~5a国内甲醇装置将供过于求,建议控制国内甲醇装置建设过热的势头,提出加快甲醇下游生物产品的开发步伐. 相似文献
79.
J.L. Rodríguez E. Pastor C.F. Zinola V.M. Schmidt 《Journal of Applied Electrochemistry》2006,36(11):1271-1279
The influence of hydrogen peroxide on the adsorption and oxidation of carbon monoxide, methanol and ethanol adlayers on porous Pt electrodes were studied in 2 M sulphuric acid solution by means of cyclic voltammetry and differential electrochemical mass spectrometry (DEMS). The oxidation of adsorbed species is observed at electrode potentials far less negative than those required for electrochemical adsorbate oxidation. The oxidation by H2O2 is dependent on its concentration in solution, as well as on the adsorbates and their coverages. In all cases the isolated adlayers are oxidised by dissolved H2O2. However, the presence of H2O2 during adsorption partially inhibits adlayer formation from CH3OH and C2H5OH, but avoids almost completely the adsorption of carbon monoxide. The removal of the residues from the surface by dissolved hydrogen peroxide probably occurs through Oad species formed during the heterogeneous decomposition reaction of H2O2 on Pt. 相似文献
80.
L. Dubau C. Coutanceau E. Garnier J-M. Léger C. Lamy 《Journal of Applied Electrochemistry》2003,33(5):419-429
The electrocatalytic oxidation of methanol was investigated on PtRu electrodes of different atomic compositions at several temperatures (from 25 to 110 °C). Very active catalyst nanoparticles supported on active carbon (Vulcan XC 72) were obtained using the colloidal synthesis developed by Bönnemann et al. [11], allowing easy variation of the atomic composition. These electrocatalysts were characterized by TEM, EDX and XRD; results indicate that they consist of platinum nanoparticles decorated by ruthenium. Methanol oxidation was studied as a function of composition, temperature and methanol concentration. Two effects were investigated: the effect of the working temperature and the effect of the atomic composition. It appeared that for lower methanol electrooxidation overvoltages, the best catalysts are ruthenium-rich, whereas at higher overvoltages the best one is the Pt + Ru (80:20)/C composition, irrespective of the working temperature, either in half-cell or in a single DMFC. 相似文献