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81.
82.
83.
Dip Singh Gill 《Journal of solution chemistry》1979,8(10):691-699
Precise conductances for tetrabutylammonium tetrabutylboride (Bu4NBBu4) at 25°C have been measured in a number of nonaqueous solvents, and the data have been analyzed by the 1957 Fuoss-Onsager conductance equation. Limiting ion conductances for the Bu4N+ ion at infinite dilution 0(Bu
4
N
+) in various solvents have been evaluated by dividing 0 values of the salt into two equal parts. The 0(Bu
4
N
+) values so obtained are in fairly good agreement (within±0.1–3.5%) with the corresponding values determined from direct transference number measurements in these solvents. 相似文献
84.
锆助剂对低温液相合成甲醇用铜铬硅催化剂性能的影响 总被引:3,自引:2,他引:3
考察了含锆的铜铬硅催化剂低温液相合成甲醇性能,并进行了BET、TPR-H2、TPD-H2、TPD-CO、XRD和XPS表征。结果表明,锆作为结构助剂及电子助剂对催化剂在低温液相合成甲醇反应中具有显著的促进作用,反应活性可提高32.25 %。锆助剂能有效提高催化剂的比表面积,促进催化剂中铜铬组分的分散及表面富集。ZrO2加入在催化剂表面产生的Cu+与催化活性的改善密切相关,Zr4+、Cr3+、Cu+可形成复合中心,为价态的稳定性提供微环境,在H2活化及C O键的断裂等反应步骤中起重要作用。 相似文献
85.
Daniel L. Obrzut Prakash M. Adekkanattu Jyothi Thundimadathil Jing Liu Delphine R. Dubois James A. Guin 《Reaction Kinetics and Catalysis Letters》2003,80(1):113-121
SAPO-34 silicoaluminophosphate molecular sieve produces large amounts of methane at elevated temperatures in the methanol
to olefins (MTO) process. This significantly reduces the lower olefins selectivity a key factor in determining the commercial
viability of this catalyst. Impregnation of the SAPO-34 molecular sieve with metal ions such as K, Cs, Pt, Ag and Ce was found
to reduce the amount of methane significantly at higher temperatures thereby increasing the lower olefins selectivity. This
observed effect is less apparent at lower temperatures where the amount of methane formed is generally low.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
86.
The kinetic study of carbonylation of methanol-acetic acid mixture to acetic acid and acetic anhydride over a cis-dicarbonylrhodium complex (MVM' Rh) coordinated with the ethylene diacrylate (M') crosslinked copolymer of methyl acrylate (M) and 2-vinylpyddine (V)shows that the rate of reaction is zero order with respect to both reactants methanol and carbon monoxide, but first order in the concentrations of promoter methyl iodide and rhodium in the complex. Polar solvents can accelerate the reaction. Activation parameters were calculated from the experimental results, being comparable to that of the homogeneous system. A mechanism similar to that of soluble rhodium catalyst was proposed. 相似文献
87.
Eng William Palumbo Anthony V. Sriharan Shobha Strandberg G. W. 《Applied biochemistry and biotechnology》1991,(1):887-899
The effect of methanol on trichloroethylene (TCE) degradation by mixed and pure methylotrophic cultures was examined in batch
culture experiments. Methanol was found to relieve growth inhibition ofMethylosinus trichosporium (OB3b) at high (14 mg/L) TCE concentrations. Degradation of TCE was determined by both radiolabeling and gas chromatography
techniques. When cultures were grown on methanol over 10 to 14 d with 0.3 mg/L TCE, OB3b degraded 16.89 ±0.82% (mean± SD)
of the TCE, and a mixed culture (DT type II) degraded 4.55±0.11%. Mixed culture (JS type I) degraded 4.34±0.06% of the TCE.
When grown on methane with 0.3 mg/L TCE, 32.93±2.01% of the TCE was degraded by OB3b, whereas the JS culture degraded 24.3
±1.38% of the TCE, and the DT culture degraded 34.3 ±2.97% of the TCE. The addition of methanol to cultures grown on methane
reduced TCE degradation to 16.21 ±1.17% for OB3b and to 5.08±0.56% for JS. Although methanol reduces the toxicity of TCE to
the cultures, biodegradation of TCE cannot be sustained in methanol-grown cultures. Since high TCE concentrations appear to
inhibit methane uptake and growth, we suggest the primary toxicity of TCE is directed towards the methane monooxygenase. 相似文献
88.
V. D. Maiorov G. I. Voloshenko N. B. Librovich M. I. Vinnik 《Russian Chemical Bulletin》1992,41(10):1768-1773
The MFTIR IR spectra of solutions of HCl in methanol were obtained in the 900–4000 cm–1 frequency range. It was found that each proton binds two molecules of methanol. The spectra exhibit intense, continuous absorption (CA) with an intensity coefficient at 2000 cm–1 of 174±10 liter/(mole·cm), which is in agreement with the corresponding coefficient for H5O
2
+
. The optical densities of CA are linear functions of the concentration of HCl at 900–1600 cm–1; there is no linearity at higher frequencies for CHCl>4 M, and there are less than two molecules of MeOH for each (MeOH)2H+ ion. The results obtained are in agreement with the model in which CA arises in solutions of strong acids because of the interaction of proton vibrations in a strong symmetric H bond with the vibrations of other groups of the proton disolvate.N. N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, 117977 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 10, pp. 2261–2268, October, 1992. 相似文献
89.
90.
直接甲醇燃料电池作为未来清洁的动力能源,由于具有下列优点:操作温度低(<100℃)、燃料易储存和运输、能量效率高、污染低和燃料启动快而受到人们广泛的关注。阳极电催化剂是直接甲醇燃料电池最重要的组成部分。本文综述了近三年来直接甲醇燃料电池阳极电催化剂最新的研究进展,主要对催化剂制备方法、新型碳载体材料、催化剂类型作了详细的评述,展望了未来甲醇电催化氧化催化剂的发展,指出了电催化剂面临的问题。 相似文献