Journal ArticleDOI
Highly active and selective Nb modified MCM-41 catalysts for Beckmann rearrangement of cyclohexanone oxime to ɛ-caprolactam
Reads0
Chats0
TLDR
In this article, a combination of various physical techniques was used for characterizing the catalysts, such as X-ray diffraction, N 2 physisorption, diffuse reflectance UV-Vis (DR-UV-Vis), Fourier transmission infra red (FT-IR), atomic emission spectroscopy (ICP-AES), and 29 Si MAS NMR (magic-angle spinning nuclear magnetic resonance) spectrographs, to confirm that Nb atoms are isolated and tetrahedrally coordinated in the framework of MCM-41.About:
This article is published in Journal of Catalysis.The article was published on 2008-11-15. It has received 51 citations till now. The article focuses on the topics: Cyclohexanone oxime & Beckmann rearrangement.read more
Citations
More filters
Journal ArticleDOI
The role of niobium component in heterogeneous catalysts
Maria Ziolek,Izabela Sobczak +1 more
TL;DR: In this paper, a review article is devoted to the materials containing niobium and modified by the addition of different metals or thio-and amino-organosilanes towards the creation of new surface properties and enhancement of catalytic activity.
Journal ArticleDOI
Niobium incorporated mesoporous silicate, Nb-KIT-6: Synthesis and characterization
TL;DR: In this paper, the direct incorporation of niobium into ordered cubic large pore mesoporous silicate with Ia3d structure, KIT-6, was demonstrated via hydrothermal synthesis using a Pluronic P123 triblock copolymer as the structure directing agent and n -butanol as additive.
Journal ArticleDOI
Catalytic performance of niobium species in crystalline and amorphous solids—Gas and liquid phase oxidation
Maria Ziolek,Piotr Decyk,Izabela Sobczak,Maciej Trejda,J. Florek,H. Golinska. W. Klimas,A. Wojtaszek +6 more
TL;DR: In this paper, the role of niobium, located in crystalline and amorphous catalysts, in catalytic oxidation reactions was investigated, and it was shown that Nb in such catalysts strongly interacts with H2O2 resulting in the formation of active O Nb(V)O2 radicals.
Journal ArticleDOI
Synthesis of N-heterocyclic compounds over zeolite molecular sieve catalysts: an approach towards green chemistry
TL;DR: Benign by Design as mentioned in this paper represents the 12 principles of green chemistry as articulated by John Warner and Paul Anastas (Green Chemistry: Theory and Practice, Oxford University Press, New York, 1998, p. 30) These principles have given chemists a framework for evaluating the chemical procedures and help chemists to develop synthetic procedures which are more efficient, create less waste, use and produce less toxic substances.
Journal ArticleDOI
Tungstated Zirconia Catalysts for Liquid-Phase Beckmann Rearrangement of Cyclohexanone Oxime: Structure-Activity Relationship
TL;DR: In this article, the performance of tungstated zirconia catalysts with different tungsten loadings and calcination temperatures for liquid-phase Beckmann rearrangement of cyclohexanone oxime to e-caprolactam was studied and the relation of their activity with the structure of polytungstate species on zircania surface was investigated.
References
More filters
Journal ArticleDOI
Studies on mesoporous materials: I. Synthesis and characterization of MCM-41
TL;DR: The mesoporous molecular sieves MCM-41 were synthesized and characterized by X-ray powder diffraction, nitrogen adsorption/desorption, cyclohexane and water adaption, transmission electron micrographs (TEM), thermogravimetric analysis (TGA), ammonia temperature-programmed desorption (TPD), FTIR, FT-Raman, 29Si, 27Al and 13C magic angle spinning (MAS) NMR spectroscopy.
Journal ArticleDOI
Niobium Compounds: Preparation, Characterization, and Application in Heterogeneous Catalysis.
Izabela Nowak,Maria Ziolek +1 more
Journal ArticleDOI
Recent advances in processing and characterization of periodic mesoporous MCM-41 silicate molecular sieves
TL;DR: A critical review of the developments in these areas with particular emphasis on adsorption characteristics, progress in controlling the pore sizes, and a comparison of pore size distributions using traditional and newer models is provided in this article.
Journal ArticleDOI
Textural Mesoporosity and the Catalytic Activity of Mesoporous Molecular Sieves with Wormhole Framework Structures
TL;DR: In this paper, three different water-alcohol cosolvent systems were used to assemble mesoporous molecular sieve silicas with wormhole framework structures (previously denoted HMS silicas) from an electrically neutral amine surfactant (S{degree}) and a silicon alkoxide precursor (I{degree).