Recyclable Platinum Nanocatalyst for Nitroarene Hydrogenation: Gum Acacia Polymer-Stabilized Pt Nanoparticles with TiO2 Support Supriya Prakash, Selvakumar Ponnusamy, Jagadeeswari Rangaraman, Kundana Nakkala, Putrakumar Balla Chemengineering, 2025 Platinum has emerged as an optimal catalyst for the selective hydrogenation of nitroarenes owing to its high hydrogenation activity, selectivity, and stability. In this study, we report the fabrication of platinum nanoparticles stabilized on a composite support consisting of gum acacia polymer (GAP) and TiO2. It was engineered for the targeted reduction of nitroarenes to arylamines via selective hydrogenation in methanol at ambient temperature. The non-toxic and biocompatible properties of GAP enable it to act as a reducing and stabilizing agent during synthesis. The synthesized nanocatalyst was characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Morphological and structural analyses revealed that the fabricated catalyst consisted of minuscule Pt nanoparticles integrated within the GAP framework, accompanied by the corresponding TiO2 nanoparticles. Inductively coupled plasma optical emission spectrometry (ICP-OES) was employed to ascertain the Pt content. The mild reaction conditions, decent yields, trouble-free workup, and facile separation of the catalyst make this method a clean and practical alternative to nitroreduction. Selective hydrogenation yielded an average arylamine production of 97.6% over five consecutive cycles, demonstrating the stability of the nanocatalyst without detectable leaching.
Gum Acacia Stabilized Ag-TiO 2and Ag-SiO 2: Sustainable Nanocatalysts for Direct and Convenient Synthesis of 5-Substituted 1 H -tetrazoles Supriya Prakash, Bojja Sreedhar, N. V. S. Naidu Synopen, 2023 We describe the use of biocompatible gum acacia (GA)-assembled Ag-TiO2 and Ag-SiO2 nanostructures as effective heterogeneous catalysts for the synthesis of 5-substituted 1H-tetrazoles through the traditional [3+2] cycloaddition of aryl nitriles with sodium azides. Characterization of the prepared catalysts employing TEM, XPS, FE-SEM, FT-IR, XRD, and TGA-DTG reveals silver nanoparticles encapsulated in the GA matrix amidst modified nano titania or silica. A variety of structurally divergent aryl nitriles were converted into the corresponding tetrazoles in a short reaction time. Other advantages include low catalytic load, easy handling of catalyst, limited use of toxic reagents, and desirable conversion yields, making this protocol a viable and practical alternative for this cyclization. The catalysts can be easily recovered and reused over multiple cycles without significant loss of catalytic activity.
Magnetic CuFe2O4 and Fe3O4 Nanoparticles Catalyzed Diacetoxylation of Alkenes and 1,2-Oxyacetoxylation of Terminal Alkynes Using PhI(OAc)2 as Oxidant B. T. V. Srinivas, P. Supriya, V. Rohithrao, N. V. S. Naidu, B. Sreedhar Chemistryselect, 2017 Magnetically retrievable CuFe2O4 and Fe3O4 nanoparticles as efficient catalysts for selective syn diacetoxylation of alkenes have been achieved using PhI(OAc)2 as oxidant under mild conditions. In addition, by using this protocol, different kinds of terminal alkynes were efficiently converted into the corresponding α‐acetoxy ketones. The catalysts were reused with consistent activity up to five cycles. To the best of our knowledge, CuFe2O4 and Fe3O4 heterogeneous catalyzed diacetoxylation of alkenes has not been studied so far.
Validated stability-indicating RP-HPLC assay method for azathioprine in pharmaceutical dosage form according to ICH guidelines International Journal of Pharmacy and Pharmaceutical Sciences, 2014
