Highly Active and Dispersed Pd Nanoparticles Stabilized by Lacunary Phosphomolybdate: Synthesis, Characterization, and Liquid Phase Hydrogenation of Levulinic Acid to γ-Valerolactone.

In the current scenario, one of the crucial reaction conversions is the synthesis of renewable biofuels and value-added chemicals from the hydrogenation of biomass. Therefore, in the present work, we are proposing aqueous phase conversion of levulinic acid to γ-valerolactone via hydrogenation using formic acid as a sustainable green hydrogen source over a sustainable heterogeneous catalyst. The catalyst based on Pd nanoparticles stabilized by lacunary phosphomolybdate (PMo11Pd) was designed for the same and characterized by EDX, FT-IR, 31P NMR, powder XRD, XPS, TEM, HRTEM, and HAADF-STEM analyses. A detailed optimization study was done to achieve maximum conversion (95% conversion), using a very small amount of Pd (1.879 × 10-3 mmol) with notable TON (2585) at 200 °C in 6 h. The regenerated catalyst was found to be workable (reusable) up to three cycles without any change in activity. Also, a plausible reaction mechanism was proposed. The catalyst exhibits superior activity against reported catalysts.

Ru-W modified graphitic carbon nitride by a monomer complexation synthesis approach from a tailored polyoxometalate: towards electrochemical detection of hydrogen peroxide released by cells.

Detection of hydrogen peroxide (H2O2) from cell cultures is important for monitoring different diseases. Here, g-C3N4 (gCN) was incorporated into well-defined clusters of RuW (RuW-gCN) through monomer complexation of Ru-substituted phosphotungstate and melamine for electrochemical detection of H2O2. RuW-gCN exhibited enhanced electrochemical sensing properties in comparison to its constituents due to the synergic effects between RuW and gCN. The characterization of RuW-gCN revealed successful complexation to form the composite in addition to the presence of a layered structure of gCN. The electrochemical sensor made of RuW-gCN was able to detect H2O2 with a detection limit of 46 nM in the linear ranges from 100 nM to 50 µM and from 50 µM to 1 mM. The developed sensor was employed for the selective detection of H2O2 in the presence of analytes like ascorbic acid (AA), dopamine, and glucose in addition to being stable even after a week of storage at room temperature. It has also been verified for real sample application by detecting H2O2 produced by cancer cells as a result of an AA trigger.

Keggin type mono Ni(II)-substituted phosphomolybdate: a sustainable, homogeneous and reusable catalyst for Suzuki-Miyaura cross-coupling.

Keggin type mono Ni(II)-substituted phosphomolybdate was synthesized and characterized by various physico-chemical techniques and used as a catalyst for Suzuki-Miyaura cross-coupling. The influence of different reaction parameters was studied, to get the maximum yield. The novelty of the present work lies in obtaining >97% yield of biphenyl in 14 h under mild reaction conditions. Although the present catalyst is homogeneous, it was regenerated and reused up to two cycles. Results demonstrated that the catalyst was effective and sustainable for cross-coupling of various halobenzenes with phenylboronic acid in aqueous medium.

Synthesis and crystal structure of an oxovanadium(IV) complex with a pyrazolone ligand and its use as a heterogeneous catalyst for the oxidation of styrene under mild conditions.

1-Phenyl-3-methyl-4-touloyl-5-pyrazolone (ligand) was synthesized and used to prepare an oxovanadium(IV) complex. The complex was characterized by single-crystal X-ray analysis and various spectroscopic techniques. The single-crystal X-ray analysis of the complex shows that the ligands are coordinated in a syn configuration to each other and create a distorted octahedral environment around the metal ion. A heterogeneous catalyst comprising an oxovanadium(IV) complex and hydrous zirconia was synthesized, characterized by various physicochemical techniques, and successfully used for the solvent-free oxidation of styrene. The influence of the reaction parameters (percent loading, molar ratio of the substrate to H(2)O(2), amount of catalyst, and reaction time) was studied. The catalyst was reused three times without any significant loss in the catalytic activity.

Novel heterogeneous catalyst, supported undecamolybdophosphate: synthesis, physico-chemical characterization and solvent-free oxidation of styrene.

A novel heterogeneous catalyst comprising undecamolybdophosphate and hydrous zirconia was synthesized, characterized by various physicochemical techniques and used as an efficient heterogeneous catalyst for oxidation of styrene using H(2)O(2) as an oxidant. The novelty of the present work lies in obtaining >99% conversion of styrene with >99% selectivity for benzaldehyde under solvent free mild reaction conditions.