@article { ISI:000347373500003, title = {Simple method for the preparation of ultra-small palladium nanoparticles and their utilization for the hydrogenation of terminal alkyne groups to alkanes}, journal = {Nanoscale}, volume = {7}, number = {3}, year = {2015}, month = {NOV}, pages = {872-876}, publisher = {ROYAL SOC CHEMISTRY}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

A simple and convenient method for the preparation of ultra-small palladium nanoparticles (Pd-NPs) by a modified digestive ripening method is described. These nanoparticles catalyse the hydrogenation of the terminal alkyne groups to alkanes selectively, and show no effect on other labile protecting and internal alkyne or internal/external alkene groups present in the molecule.

}, issn = {2040-3364}, doi = {10.1039/c4nr04239e}, author = {Seth, Jhumur and Kona, Chandrababu Naidu and Das, Shyamsundar and Bhagavatula L. V. Prasad} } @article {42668, title = {Bromide ion mediated modification to digestive ripening process: preparation of ultra-small Pd, Pt, Rh and Ru nanoparticles}, journal = {Nano Research}, volume = {9}, year = {2016}, month = {MAY}, pages = {2007{\textendash}2017}, abstract = {

Nanoparticles of catalytically important transition metals, such as Pd, Pt, Rh, and Ru have been prepared by the well-known {\textquotedblleft}digestive ripening{\textquotedblright} (DR) and {\textquotedblleft}modified digestive ripening{\textquotedblright} (mDR) methods. In the traditional DR process, a polydisperse colloidal dispersion is refluxed in the presence of a surface-active molecule, such as alkanethiol. The mDR method involved a small modification in the procedure, wherein refluxing was performed with an alkanethiol and a tetra-alkylammonium bromide surfactant. This minor modification led to a dramatic change in the final particle size distributions, giving access to nanoparticles in the \<3 nm size regime; this was not possible with the traditional DR process. Bromide ions, which are present during refluxing, proved to be an important ingredient in the modification process. These bromide ions are revealed to act as etchants, resulting in ultra-small nanoparticles. All transition metal nanoparticles investigated displayed catalytic activity in the reduction reaction of p-nitro phenol. Pd nanoparticles, synthesized by a modified digestive ripening method, exhibited the best catalytic activity among the systems investigated.

}, doi = {10.1007/s12274-016-1091-0}, author = {Seth, Jhumur and Bhagavatula L. V. Prasad} } @article {44225, title = {Preparation of metal oxide supported catalysts and their utilization for understanding the effect of a support on the catalytic activity}, journal = {New Journal of Chemistry}, volume = {42}, year = {2018}, month = {JAN}, pages = {402-410}, type = {Article}, abstract = {

A convenient way of anchoring transition metal nanoparticles (palladium, platinum, rhodium and ruthenium) onto metal oxide supports (magnesium oxide and zirconium oxide) by means of a modified sol-gel technique is demonstrated. Use of toluene dispersed, ligand protected pre-synthesized nanoparticles during sol-gel synthesis delivered size-controlled, spatially distributed, well-adhered transition metal nanoparticles (MNPs) on metal oxide supports. The catalytic activities of these supported nanoparticles were tested for the p-nitro phenol reduction reaction. It was observed that the reaction kinetics were crucially dependent on the catalyst support and MNP size. The influence of the magnesium oxide and zirconium oxide supports towards the catalytic performance of the anchored transition MNPs was probed using cyclic voltammetry and the differences in the same were attributed to the support-induced modification in the electronic properties of the MNPs. Our results indicated that magnesium oxide is a better support than zirconium oxide.

}, issn = {1144-0546}, doi = {10.1039/c7nj03753h}, author = {Seth, Jhumur and Dubey, Prashant and Chaudhari, Vijay R. and Prasad, Bhagavatula L. V.} }