Authors:Guangle Zhao, Liang Yu, Xilong Yan, Yang Li, Donghua Wang, and Ligong Chen
The catalytic synthesis of 2-amino-1-butanol from 1,2-butanediol and ammonia was studied in a continuous fixed-bed reactor.
The catalysts prepared by doping Co–Ba/γ-Al2O3 with Sr, Ni, Ca, Zn, La, Fe, Mg, Zr, Mn, Cr were examined, among which the Co–Ba–Fe/γ-Al2O3 catalyst showed the best catalytic performance. These catalysts were characterized by XRD, XPS, and TPR. It was found that
the addition of iron led to the formation of crystalline Co7Fe3, which modified the catalytic activity of Co species, inhibited the generation of CoAl2O4, improved the stability and enhanced the reduction of the Co–Ba–Fe/γ-Al2O3 catalyst. The conversion of 1,2-butanediol was 72.9% and the selectivity of 2-amino-1-butanol achieved 73.3% under the optimum
Authors:Dimitrinka Nikolova, Rumeana Edreva-Kardjieva, and Tatyana Grozeva
by alkaline metals [ 23 ] are so far less investigated. This fact directed us to study systematically the state of (K)(Ni)Mo/γ-Al2O3 catalysts as one-, bi- and tri-component samples [ 24 – 27 ].
Introduction of potassium and nickel was
Authors:Tugba Davran-Candan, Mehtap Demir, and Ramazan Yildirim
reaction rates were used to identify the possible reaction mechanism.
Experiments were performed with 0.5 wt. % Au/γ-Al2O3 catalyst prepared by the homogeneous deposition
Authors:K. Iwai, M. Katada, H. Sano, and Y. Iwasawa
Characterization of Fe3/CO/12 cluster adsorbed on -Al2O3 and SiO2 was undertaken by means of57Fe-Mössbauer spectroscopy. In the case of Fe3/CO/12 adsorbed on -Al2O3, iron atoms were found to be similar to metallic iron. Fe3/CO/12 adsorbed on SiO2 retains its original molecular structure and chemical nature.
Authors:J. Liu, H. Xu, W. Shen, X. Pan, and Y. Xiang
Mn2O3/-Al2O3 catalysts were prepared by the impregnation method, and the maximum monolayer dispersion capacity or dispersion threshold value of Mn2O3 on the surface of -Al2O3 was determined to be 13.08% from the decomposition mass loss of supported Mn(NO3)2 in the monolayer state. This was compared with the values estimated from a close-packed monolayer model and an interaction model. It was confirmed that the high activities and selectivities of the catalysts for benzoic acid hydrogenation to benzaldehyde are due to the monolayer dispersion of the Mn2O3 on the surface of -Al2O3.
Authors:A. Ren, S. Yu, J. Han, P. Chang, C. Chen, J. Chen, and X. Wang
Humic substances have attracted great interest in the investigation of metal ion behavior in the environment because of their
special properties. Sorption and complexation of Pb2+ on MX-80 bentonite, LA bentonite, alumina and silica as a function of pH were studied in the presence and absence of fulvic
acid (FA). The experiments were carried out in 0.01M and 0.001M NaNO3 solutions under ambient conditions. The results indicate that sorption of Pb2+ on the solid samples is strongly dependent on pH and FA. The sorption of Pb2+ is not influenced drastically by ionic strength. The nature of minerals/oxides, nature of humic substances and the composition
of the solution are important factors in the behavior of metal ions in the environment. The results also indicate that FA
has a positive effect on Pb2+ sorption at low and a negative effect at high pH values, and the results are discussed in the comparative complexation between
FA-Pb2+ and Pb2+-minerals.
Authors:Viorel Chihaia, Karl Sohlberg, M. Scurtu, C. Hornoiu, M. Caldararu, C. Munteanu, G. Postole, N. I. Ionescu, T. Yuzhakova, and A. Redey
, charge and coverage of the surface, and correspondingly the apparent relative dielectric constant of the surface layer, including the adsorbed phase.
Studies of SnO 2 /γ-Al2O3 systems are infrequent in the literature and mostly in connection