National Chemical Laboratory

About: National Chemical Laboratory is a facility organization based out in Pune, Maharashtra, India. It is known for research contribution in the topics: Catalysis & Nanoparticle. The organization has 8891 authors who have published 14837 publications receiving 387600 citations.

XANES and EXAFS analysis of copper ion-exchanged ZSM-5 zeolite catalyst used for nitrogen monoxide decomposition

Abstract: XANES and EXAFS analysis of Cu ion-exchanged ZSM-5 zeolite, a highly active catalyst for NO decomposition, is performed. The copper species in the zeolite are Cu(II) ions in the zeolite cages. The contribution of Cu-Cu local structure is suggested for high loading samples. The Cu atoms in the zeolite are more ionic than CuO. The analysis of the catalyst deactivated by SOx treatment suggests the presence of Cu atoms surrounded by SO4 ions which blocks the adsorption of NO molecules.

Synthesis of tin-silicalite molecular sieves with MEL structure and their catalytic activity in oxidation reactions

Abstract: Tin-containing, medium pore molecular sieves (Si/Sn ratios above 40) with MEL structure have been syntheszed hydrothermally and characterized by a variety of techniques. Changes in unit cell volume (XRD) account for about 20% of Sn 4+ ions in possible tetrahedral positions. 119 Sn MAS-NMR spectra, however, indicate that these are mostly in octahedral coordination. Framework IR spectra show an absorption at 970 cm −1 which is associated with Si O Sn vibration. Despite the uncertainty of the environment of the Sn 4+ ions in the silicalite structure, these tin-silicates are found to be quite active in the hydroxylation of phenol and toluene with aqueous H 2 O 2 as oxidant. The product distribution suggests that most of the Sn 4+ ions are located within the channels of the MEL structure.

Somatic embryos from protoplasts of loblolly pine proembryonal cells

Abstract: We report a method for regenerating somatic embryos from protoplasts derived from a cell suspension culture containing proliferating embryonal–suspensor masses (ESMs) of developing loblolly pine seeds. Uniform, highly viable and morphogenic protoplasts from embryonal cells contained a dense neocytoplasm as judged by strong acetocarmine staining. Culture qf protoplasts in a thin layer of agarose in a medium using high levels of myo–inositol contributed to the proliferation of colonies of proembryonal cells with large nuclei, which in turn yielded new ESMs. When protoplast–derived ESMs were placed on agar plates, somatic embryos were recovered within 8 to 10 weeks by somatic polyembryogenesis. After a total of 15 weeks an initial crop of over 100 somatic embryos could be regenerated by a conifer–type developmental plan from an initial population of 105 protoplasts.