Vanadium oxide based materials: Synthesis, characterization and catalytic nitrogen oxide abatement properties

Polyoxovanadates and their derivatives are an emerging class of materials of immense current interest. Chapter I is an introduction to the research described in this thesis and describes the need for this research towards the development of new vanadium oxide based materials with desirable properties that can cater the pressing environmental concerns and industrial needs.; Chapter II describes the synthesis, characterization, thermal, optic and magnetic properties of a series of novel cationic heteropolyoxovanadium (IV) cluster containing previously unobserved fully reduced metallacyclic core---{lcub}MV6N6O18{rcub}---exhibiting the Anderson structure and functionalized with triethanolamine ligands. And an unprecedented novel fully reduced and completely functionalized neutral mixed metal octametalate species. With the help of these materials we were able to establish the pattern in magnetic behavior and map the changes in materials from Para - Ferro magnetic just by the interchange of heterometal ions present in the cavity formed by the reduced cyclic hexavanadate system.; Chapter III deals with the synthesis of a wide array of materials that range from molecular, nano-dimensionalised supramolecules to layered and three-dimensional solids utilizing the process of self-assembly in presence of both organic and inorganic linkers. These materials were made using conventional and solvothermal synthetic techniques, where slight changes in pH, solvent mixture, temperature and the amines used made a tremendous difference in the products that were obtained.; Chapter IV describes a systematic study of evaluating the deNOx catalytic potential of several representative vanadium oxide based materials. We tested representative OFMs composed of {lcub}V18O 42[XO4]{rcub} building block units connected by -O-M-O- linkage [M = Mn, Fe, Co, and Ni; X = V, S] and vanadium oxide molecular materials under different HC-SCR conditions. The catalytic properties of these new materials have also been compared with Cu-ZSM-5, activated carbon, V2O 5 and V2O3. The active catalyst phase of the catalyst materials giving the best deNOx activity and having increased tolerance to oxygen was characterized using several analytical techniques such as BET Surface Area, FT-IR, Elemental Analysis, Temperature Programmed Reduction and Oxidation (TPR & TPO), SEM, and XRD Patterns. This study shows that novel vanadium oxide based materials are indeed promising materials for molecular magnets and HC-SCR deNOx catalysts.