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91.
Ramakul Prakorn Songkun Eakkapit Pattaweekongka Weerawat Hronec Milan Pancharoen Ura 《Korean Journal of Chemical Engineering》2006,23(1):117-123
The transport of Co(II) through hollow-fiber-supported liquid membrane containing di-(2-ethylhexyl) phosphoric acid (D2EHPA)
diluted in kerosene was examined. The mass transfer rate, expressed as permeability, P, focused on diffusion through the aqueous
layer in the feed solution, the organic layer and the aqueous layer in the stripping solution. Experiments were performed
as a function of aqueous feed solution velocity (100-500 ml/min), carrier concentration (0.1-20% v/v), aqueous stripping solution
velocity (100-1,000 ml/min) and feed concentration (100-1,000 ppm) with 0.1 M HCl in the product phase. pH of the feed solution
was 5.0. The measured permeabilities were compared to generally accepted mass transfer correlations. The validity of the prediction
was evaluated with the experimental data, and the data were found to tie in well with the theoretical values. The model is
the reported describing that the rate limiting step in the transport of the ion was the diffusion through both aqueous films,
feed and stripping, whereas the organic resistance of the membrane was negligible. From this study, the model has good potential
for the prediction of permeability of Co(II). 相似文献
92.
钴白合金湿法冶金工艺研究 总被引:11,自引:1,他引:11
本文研究了钴白合金湿法冶炼工艺流程,详细进行了氯气浸出-电溶脱铜-TBP萃取除铁试验研究。试验条件下,钴、铜、铁浸出率均达到99%,且分离效果良好。文章给出了钴白合金冶炼原则工艺流程。 相似文献
93.
以间苯二酚和乙酰乙酸乙酯为原料,在浓硫酸的催化下合成7-羟基-4-甲基香豆素。以4-硝基邻苯二甲酰亚胺为原料,通过氨水催化开环,三氯氧磷脱水制得4-硝基邻苯二甲腈。得到的7-羟基-4-甲基香豆素和4-硝基邻苯二甲腈经过亲核取代反应得到7-(3,4-二氰基苯氧基)-4-甲基香豆素。考察了7-羟基-4-甲基香豆素和4-硝基邻苯二甲腈的投料比、缚酸剂用量、反应温度和反应时间对反应的影响,最优反应条件为:n(7-羟基-4-甲基香豆素)∶n(4-硝基邻苯二甲腈)∶n(无水碳酸钾)=1.4∶1.0∶1.5,反应温度30℃,反应时间14 h,收率为63.7%,并通过红外吸收光谱、核磁共振氢谱和高效液相色谱(色谱纯度为99.30%)对合成的化合物的结构进行了确证。在该条件下适当放大实验条件得到收率基本在83.1%,比文献报道收率68%要高。 相似文献
94.
双核酞菁铁催化t-BHP氧化环己烷性能研究 总被引:1,自引:2,他引:1
考察了实验室自制的酰亚胺基取代双核酞菁铁(FeBPcN)催化氧化环己烷的性能,所用氧化剂为叔丁基过氧化氢,探讨了反应时间、反应温度、催化剂用量、溶剂、氧化剂用量及加入方式对该催化反应的影响。得出实验室自制的双核酞菁铁催化氧化环己烷的最优化条件为:反应压力:常压;反应温度:25℃;反应时间:20h;环己烷用量:2mL;催化剂用量:0.02g;氧化剂用量:10mLt-BHP;氧化剂加入方式:1.25mL/h滴加。自制酰亚胺基取代双核酞菁铁与卟啉铁、酞菁铁相比,催化性能无明显差别且容易回收,回收一次和回收两次后酮醇产率分别为17.0和17.1,仍能保持原有的催化氧化性能。 相似文献
95.
Jian-Qiang Zeng Sheng-Nan SunJing-Ping Zhong Xiao-Feng LiRui-Xiang Wang Li-Na WuLi Wang You-Jun Fan 《International Journal of Hydrogen Energy》2014
The hydrothermal synthesis of a novel Pd electrocatalyst using copper phthalocyanine-3,4′,4″,4′″-tetrasulfonic acid tetrasodium salt (TSCuPc) functionalized multi-walled carbon nanotubes (MWCNTs) composite as catalyst support for Pd nanoparticles is reported. The prepared nanocomposites were characterized by UV–vis absorption spectroscopy, Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, thermogravimetric analysis (TGA), X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and electrochemical tests. It is found that Pd nanoparticles are uniformly deposited on the surface of TSCuPc-MWCNTs, and their dispersion and electrochemical active surface area (ECSA) are significantly improved. Studies of cyclic voltammetry and chronoamperometry demonstrate that the Pd/TSCuPc-MWCNTs exhibits much higher electrocatalytic activity and stability than the Pd/AO-MWCNTs catalyst for formic acid oxidation. This study implies that the as-prepared Pd/TSCuPc-MWCNTs will be a promising candidate as an anode electrocatalyst in direct formic acid fuel cell (DFAFC). 相似文献
96.
97.
M. D. Joseph Sebastian B. Rudraswamy M. C. Radhakrishna Ramani 《Bulletin of Materials Science》2003,26(5):509-515
Cobalt ferrite (CoxFe3?xO4) is prepared in powder form by thermal decomposition of iron and cobalt salts and is analysed by X-ray diffraction and Mössbauer spectroscopic techniques. The variation of Mössbauer parameters, lattice parameters and crystallite size of the products formed with variation in the composition of Fe and Co ratios are studied. The studies confirm the formation of nano-size cobalt ferrite particles with defect structure and it is found to be maximum for the Fe : Co = 60 : 40 ratio of the initial precursor oxides. 相似文献
98.
《International Journal of Hydrogen Energy》2020,45(7):4587-4595
An effective bi-functional electrocatalyst of Co3O4/Polypyrrole/Carbon (Co3O4/Ppy/C) nanocomposite was prepared through a simple dry chemical method and used to catalyze the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Three types of carbon support as Vulcan carbon, reduced graphite oxide (RGO) and multi-walled carbon nanotubes (MCNTs) were used to study the influence on electrochemical reactions. Spherical shaped Co3O4 nanoparticles with 8–10 nm was found uniformly distributed on Ppy/C composite, which were analyzed by X-ray diffraction and transmission electron microscopy techniques. Amongst, Co3O4/Ppy/MWCNT shows improved bifunctional electrocatalytic activity towards both OER and HER with relatively low over potential (340 mV vs. 490 mV at 10 mA cm−2) and Tafel slope (87 vs. 110 mV dec−1). In addition to that, MWCNT supported Co3O4/Ppy nanocomposite exhibits good electronic conductivity and electrochemical stability up to 2000 potential cycles. The results clearly indicate that the Co3O4/Ppy/MWCNT nanocomposite could be the promising bi-functional electrocatalyst for efficient water electrolysis. 相似文献
99.
100.
Dewi Tristantini Sara Lögdberg Börje Gevert Øyvind Borg Anders Holmen 《Fuel Processing Technology》2007
The Fischer–Tropsch synthesis over Co/γ-Al2O3 and Co–Re/γ-Al2O3 was investigated in a fixed-bed reactor at 20 bar and 483 K using feed gases with molar H2/CO ratios of 2.1, 1.5 and 1.0 simulating synthesis gas derived from biomass. With lower H2/CO ratios in the feed, the CO conversion and the CH4 selectivity decreased, while the C5+ selectivity and olefin/paraffin ratio for C2–C4 increased slightly. The water–gas shift activity was low for both catalysts, resulting in high molar usage ratios of H2/CO (close to 2.0), even at the lower inlet ratios (i.e. 1.5 and 1.0). For both catalysts, the drop in the production rate of hydrocarbons when shifting from an inlet ratio of 2.1 to 1.5 was significant mainly because the H2/CO usage ratio did not follow the change in the inlet ratio. The hydrocarbon selectivities were rather similar for inlet H2/CO ratios of 2.1 and 1.5, while significantly deviating from those for an inlet ratio of 1.0. With the studied catalysts, it is possible to utilize the advantages of an inlet ratio of 1.0 (higher selectivity to C5+, lower selectivity to CH4, no water–gas shifting of the bio-syngas needed prior to the FT reactor) if a low syngas conversion is accepted. 相似文献