Energieumwandlung: Ein Cobalt‐Redoxvermittler Co(bpyPY4)2+/3+ mit sechszähnigem Polypyridyl‐Liganden wurde entwickelt. Farbstoff‐Solarzellen (DSCs) mit diesem Redoxvermittler zeigen eine etwas höhere ...Effizienz als Co(bpy)32+/3+‐Zellen, und eine Untersuchung der Langzeitstabilität der Co(bpyPY4)2+/3+‐DSCs belegt ihre hervorragende Stabilität bei voller Bestrahlung (siehe Bild).
Heterogeneous oxidation of liquid cyclohexane by molecular oxygen was carried out over metal-containing ZSM-5 catalysts in a solvent-free system. Among those M-ZSM-5 and M/ZSM-5 catalysts tested, ...Co-containing ZSM-5 catalysts including Co/ZSM-5 (prepared by ion-exchange and calcination) and Co-ZSM-5 (prepared by ion-exchange and drying) showed the best activity for the oxidation of cyclohexane to cyclohexanone and cyclohexanol. Co/ZSM-5 had almost the same activity as Co-ZSM-5 for the cyclohexane oxidation; however, the leaching of cobalt from Co-ZSM-5 readily occurred. Co/ZSM-5 (calcined) catalyst could achieve about 10
mol% conversion of cyclohexane and 97% selectivity of KA-oil (the mixture of cyclohexanone and cyclohexanol) at 393
K under the pressure of 1.0
MPa O
2. In addition, other factors like the temperature, the pressure, the time, various metals, the
tert-butylhydroperoxide (TBHP) addition, and the catalyst reuse were investigated carefully. For the titled oxidation, Co/ZSM-5 was recyclable, and could behave as a truly heterogeneous catalyst.
TiO2-supported Cobalt and cobalt–phosphorus catalysts prepared by impregnation are characterized by XRD, XPS, Laser Raman Spectroscopy (LRS), and Diffuse Reflectance Spectroscopy (DRS) and ...investigated in ethane oxidative dehydrogenation (ODH). At low cobalt loadings, the carrier is essentially covered by octahedral Co2+ ions, whereas at concentrations superior to 3.7 wt% formation of the Co3O4 spinel is observed. The best performance in ethane ODH is achieved at 550°C with the sample containing 7.6 wt% Co. The reaction begins with a conversion of 33% and a selectivity around 75%, then it decreases to reach after 150 min on stream a stationary state at 22% of conversion and 60% selectivity. This loss of 30% of the initial activity may be associated with a decrease of the specific surface area and the concomitant formation of CoTiO3 and Co2TiO4, as revealed by LRS, in situ DRS, and XPS analysis. The activity in ethane ODH seems to be mainly related to the presence of Co2+ ions octahedral sites. Addition of phosphorus to Co(7.6)/TiO2 catalysts results in the reduction of Co3+ ions and a growth of amorphous cobalt–phosphorus compounds which provoke a severe decrease of the catalyst performance.
Bu çalışmada, vakum/argon altında hazırlanan atomik olarak eşit miktarda Fe ve Co içeren 50Fe-50Co ikili alaşımı kutu borlama yöntemi ile 800 °C, 900 °C ve 1000 °C’de 6 sa. süre ile kaplanmıştır. ...Oluşturulan kaplamanın mikroyapısı, faz bileşimi, sertliği, kaplamanın kimyasal bileşimi, X-ray kırınımı, optik mikroskop, taramalı elektron mikroskobu, mikrosertlik cihazlarıyla karakterize edilmiştir. Her üç sıcaklıkta da kaplama tabakasının altlık malzemeye çok mükemmel yapıştığı ve testere dişi morfolojisine sahip borür tabakanın oluştuğu tespit edilmiştir. Kaplama Fe2B ve Co2B fazlarından oluşmuştur. Kobalt elementinin kaplama içerisinde homojen şekilde dağılmış olduğu tespit edilmiş. Kaplama kalınlığı sıcaklığa bağlı olarak artmıştır. Yoğun borür tabakanın sertliği kaplama kalınlığı boyunca değişmemiştir.
Bu çalışmada, vakum/argon altında hazırlanan atomik olarak eşit miktarda Fe ve Co içeren 50Fe-50Co ikili alaşımı kutu borlama yöntemi ile 800 °C, 900 °C ve 1000 °C’de 6 sa. süre ile kaplanmıştır. ...Oluşturulan kaplamanın mikroyapısı, faz bileşimi, sertliği, kaplamanın kimyasal bileşimi, X-ray kırınımı, optik mikroskop, taramalı elektron mikroskobu, mikrosertlik cihazlarıyla karakterize edilmiştir. Her üç sıcaklıkta da kaplama tabakasının altlık malzemeye çok mükemmel yapıştığı ve testere dişi morfolojisine sahip borür tabakanın oluştuğu tespit edilmiştir. Kaplama Fe2B ve Co2B fazlarından oluşmuştur. Kobalt elementinin kaplama içerisinde homojen şekilde dağılmış olduğu tespit edilmiş. Kaplama kalınlığı sıcaklığa bağlı olarak artmıştır. Yoğun borür tabakanın sertliği kaplama kalınlığı boyunca değişmemiştir.
Bu çalışmada, vakum/argon altında hazırlanan atomik olarak eşit miktarda Fe ve Co içeren 50Fe-50Co ikili alaşımı kutu borlama yöntemi ile 800 °C, 900 °C ve 1000 °C’de 6 sa. süre ile kaplanmıştır. ...Oluşturulan kaplamanın mikroyapısı, faz bileşimi, sertliği, kaplamanın kimyasal bileşimi, X-ray kırınımı, optik mikroskop, taramalı elektron mikroskobu, mikrosertlik cihazlarıyla karakterize edilmiştir. Her üç sıcaklıkta da kaplama tabakasının altlık malzemeye çok mükemmel yapıştığı ve testere dişi morfolojisine sahip borür tabakanın oluştuğu tespit edilmiştir. Kaplama Fe2B ve Co2B fazlarından oluşmuştur. Kobalt elementinin kaplama içerisinde homojen şekilde dağılmış olduğu tespit edilmiş. Kaplama kalınlığı sıcaklığa bağlı olarak artmıştır. Yoğun borür tabakanın sertliği kaplama kalınlığı boyunca değişmemiştir.
A generalized systhesis method has been developed and demonstrated to have the potential to generate many transition-metal-rich zeolite-type structures. The method has been used to make zeolite ...analogues based on cobalt phosphate with diverse chemical compositions and structure types.
Oxides of cobalt supported on various supports such as SiO2 and Al2O3 have been prepared by using incipient wetness technique (IMP), the sol–gel (SG) route and the combination of the two methods ...(ISG). The solids formed, after calcination of the corresponding precursors, were characterised by X-ray diffraction, BET area measurements, metal dispersion, and by X-ray photoelectron spectroscopy. Using metal loading of 8%, a high catalytic activity was demonstrated for ethanol steam reforming. Products distribution of the reaction has been found to be dependent on the nature of the support and of the preparation method of the catalysts.
Some new transition metal complexes of ciprofloxacin-imines derived from ciprofloxacin and p-substituted anilines were
synthesized and characterized on the basis of physical properties, conductance ...measurements, elemental analysis, UV/Vis., infrared
and nuclear magnetic resonance spectroscopy. These ligands as-well as their metal complexes were also evaluated for their
antibacterial activity against several bacterial strains, such as Staphylococcus aureus, Bacillus subtilus, Salmonella typhae, and £. coll
It was found that metal complexes are more antibacterial as compared to uncomplexed ligands. The present study was carried out
in search of a target antibiotic instead of a broad spectrum one.
Cobalt salophen (N, N′-bis (salicylidene)o-phenylenediamine) complex was immobilized in the montmorillonite. The montmorillonite was characterised by atomic absorption spectroscopic (AAS) analysis, ...Fourier transform infrared (FT-IR), diffuse reflectance UV–vis, powder-X-ray-diffraction (PXRD) and X-ray photoelectron spectroscopy (XPS) measurements. The catalytic activity of the novel cobalt salophen based materials was tested in the epoxidation of cyclohexene in the isobutyraldehyde/air system using acetonitrile as solvent and very high TOF value (10.1 min
−
1
) was obtained. Various reaction conditions were studied. The experimental results indicated very good catalytic activity and selectivity in the epoxidation of cyclohexene. Repeated runs of the catalysts were carried out five times and the results indicated that the catalyst was stable for the epoxidation of cyclohexene.
