@article {45731, title = {Exploration of amination reactions on highly extendable active sites of Pd(II)-3-allylsalicylaldiminophenol (ASIP) complex over thiofunctionalized SBA-15}, journal = {Microporous and Mesoporous Materials}, volume = {242}, year = {2017}, month = {APR}, pages = {173-181}, type = {Article}, abstract = {

An effective and impressive heterogeneous catalyst, Pd(II)-3-allylsalicylaldiminophenol-SBA-15, dubbed as Pd(II)ASIP@SBA-15, for amination reactions of aryl halides to synthesize secondary amines (2), has been synthesized and characterized. Pd(II)ASIP@SBA-15 has been synthesized by the covalent anchoring of 3-allylsalicylaldehyde over thiofunctionalized SBA-15, then further reaction with 2-aminophenol, followed by metallation process by using Pd(11)(OAc)(2). A specifically designed cheap and easily available organic ligand, 3-allylsalicylaldiminophenol (ASIP), was synthesized from 3-allylsalicylaldehyde and 2-aminophenol. Using this, the synthesis of Pd(II)ASIP@SBA-15 was carried out whereby the ligand providing an active co-ordination or chelating sites for palladium metal. This strategy helped in exposing the Pd(11)ASIP active sites from surface to channels of SBA-15 support during the reactions. The synthesized catalyst were characterized by CHN analysis, PXRD, Nitrogen sorption analyses, TG \& DTA, FTIR, C-13 and Si-29 CPMASS NMR spectra, XPS, UV-Visible, SEM, EDAX and TEM. Pd(II)ASIP@SBA-15 catalyst was screened in heterogeneous amination reactions of aryl halides to produce N-aryl derivatives or secondary amines with high catalytic activity as revealed by turn over frequency (TOF) calculations. To explore the heterogeneous nature of catalysts, amination reactions were carried with neat Pd(II)ASIP complex and Pd(11)(OAc)(2) catalysts. The catalyst was recycled several times without much loss of activity and Sheldon hot filtration test has been performed. (C) 2017 Elsevier Inc. All rights reserved.

}, keywords = {Amination Reactions, heterogeneous catalysis, Reusable, Supported catalysis}, issn = {1387-1811}, doi = {10.1016/j.micromeso.2017.01.026}, author = {Lazar, Anish and Vinod, C. P. and Singh, A. P.} } @article {45419, title = { Enhanced selectivity of 3-D ordered macroporous Pt/Al2O3 catalysts in nitrites removal from water}, journal = {Applied Catalysis A-General}, volume = {564}, year = {2018}, month = {AUG}, pages = {26-32}, type = {Article}, abstract = {Tailored macroporous mesoporous alumina supports have been successfully prepared using a single hard templating approach. Pt nanoparticles, showing similar physico-chemical properties, were homogeneously dispersed throughout the different alumina frameworks as catalytic active phase for drinking water treatment. We demonstrated that careful modification of pore properties of the catalyst (size and connectivity) by pseudomorphic transformation can strongly modulate the reaction rate and selectivity through the limited access to Pt active sites within the alumina porous particles. Specifically, 3-D Ordered Macroporous Pt-Al2O3 catalysts with a high degree of interconnectivity yield to superior catalytic properties (enhanced activity and selectivity) over pure mesoporous counterparts in the hydrogenation of nitrites in water. We found that large pores (240 nm) interconnected with windows (110 nm) alleviate mass transfer limitations and clearly improve NZ selectivity. The findings of this study further suggest the possibility of engineering the pore architecture of the support to fine tune the selectivity for a particular reaction rather than investigating more on tuning the properties of the costly active metallic phase.}, doi = {10.1016/j.apcata.2018.07.014}, author = {Sekhar, A. C. Sunil and Zaki, A. and Troncea, S. and Casale, S. and Vinod, C. P. and Dacquin, J. P. and Granger, P.} } @article {46837, title = {Engineering pore morphology using silica template route over mesoporous cobalt oxide and its implications in atmospheric pressure carbon dioxide hydrogenation to olefins}, volume = {19}, year = {2020}, month = {JUN}, pages = {100586}, type = {Article}, abstract = {

Highly ordered mesoporous cobalt oxides (denoted as m-Co-KIT-6 and m-Co-SBA-15) with three dimensional and two dimensional pore morphology respectively have been synthesized using 3D KIT-6, and 2D SBA-15 as silica template via nanocasting route. CO2 hydrogenation activity was evaluated for these mesoporous materials under atmospheric pressure conditions. In comparison to nanoparticles of cobalt oxide (Co3O4-nano), mesoporous catalysts showed excellent activity for CO2 hydrogenation due to their higher number of exposed active sites and lower mass diffusion limitations. The ordered mesoporous structure of Co3O4 catalysts favored the chain growth of carbon atoms for the production of C2+ hydrocarbons while Co3O4 nanoparticles showed strong selectivity toward CH4. High selectivity for C2+ (similar to 25\%) was obtained for both m-Co-KIT-6 and m-Co-SBA-15 catalysts at 320 degrees C. In addition, the 3D pore structure of m-Co-KIT-6 catalyst exclusively formed more olefins (54.9\%) fraction. (C) 2020 Published by Elsevier Ltd.

}, keywords = {CO2 hydrogenation, Mesoporous CO3O4, Olefin fraction, Pore morphology, Silica hard template}, issn = {2352-9407}, doi = {10.1016/j.apmt.2020.100586}, author = {Gupta, Sharad and Ciotonea, Carmen and Royer, Sebastien and Dacquin, Jean-Philippe and Vinod, C. P.} } @article {49282, title = {Exploring the CeO2 support morphology for the carbon dioxide hydrogenation reaction using nickel catalysts}, journal = {Journal of Physical Chemistry C}, volume = {128}, year = {2024}, month = {OCT}, pages = {18782-18792}, type = {Article}, abstract = {

The catalytic activity and stability are examined for the hydrogenation of carbon dioxide under atmospheric pressure over 2 wt \% Ni/CeO2 nanorods (2Ni-CeNRs), nanocubes (2Ni-CeNCs), and nanopolyhedra (2Ni-CeNPs). The 2Ni-CeNR catalysts display excellent catalytic activity and higher stability compared with 2Ni-CeNC and 2Ni-CeNP catalysts. A comprehensive understanding of the surface atomic and electronic structure versus activity has been derived using high-resolution electron microscopy and spectroscopy techniques. High metal dispersion, strong metal-support interaction (SMSI) effect and abundant oxygen vacancies are deduced to play a crucial role in determining the catalytic activity and selectivity of the CO2 hydrogenation reaction.

}, issn = {1932-7447}, doi = {10.1021/acs.jpcc.4c05258}, author = {Gupta, Sharad and Jagtap, Anuradha and Vinod, C. P.} } @article {49420, title = {Enhanced light-matter interaction in gas nitridation-derived TiNx thin films for potential plasmonic applications}, journal = {Journal of Materials Science}, volume = {60}, year = {2025}, month = {JAN}, pages = {178-194}, type = {Article}, abstract = {

Titanium nitride is a substitute material exhibiting improved opto-electrical characteristics suitable for plasmonic purposes with adjustable attributes. In this study, we have embraced an innovative methodology for the fabrication of titanium nitride thin coatings via the nitridation of RF magnetron-sputtered titanium metallic films for surface plasmon resonance utilisation. The augmented electrical and optical features of TiN thin coatings prepared through the nitridation procedure are reported for the first time. The metallic coatings underwent gas nitridation at diverse temperatures within the range of 450-600 degrees C. The titanium nitride phase evolution in the coatings was corroborated by x-ray diffraction and x-ray photoelectron spectroscopy examinations. The dielectric function is deduced from reflection spectra through Drude-Lorentz model fitting, and the manifestation of surface plasmon excitation in the visible region was confirmed by correlating with carrier concentration assessments and by ensuring the required negative permittivity in the region. The red shift of screened plasma wavelength was observed with the nitridation temperature, and the same is varied in the wavelength range 400-700 nm. Ultimately, surface plasmons were excited in coatings with optimised thickness using Kretschmann configuration in wavelength interrogation mode.

}, issn = {0022-2461}, doi = {10.1007/s10853-024-10520-y}, author = {Tony, Liya and Selvam, I. Packia and Vinod, C. P. and Potty, S. N.} } @article {49914, title = {Exploring the electronic modulation in controlling the activity and selectivity of Ni-Au-In based catalyst in atmospheric pressure CO2 hydrogenation}, journal = {Chemical Engineering Journal}, volume = {520}, year = {2025}, month = {SEP }, pages = {165921}, type = {Article}, abstract = {

Nickel-based catalysts are widely used for the hydrogenation of CO2 but encounter stability challenges during prolonged reactions and at elevated temperatures. At atmospheric pressure, nickel primarily promotes methane formation in CO2 hydrogenation reactions. In this work, we demonstrate that the stability and activity of nickel can be significantly enhanced through gold (Au) modification. Furthermore, we achieve a near-complete selectivity switch from methane to CO by incorporating indium (In), mediated through the formation of Au-In alloy. This catalyst exhibits excellent CO2 conversion and CO selectivity at relatively lower temperatures (400 degrees C), addressing a major bottleneck in the Reverse Water-Gas Shifts (RWGS) reaction. XPS studies demonstrate an interesting electron transfer mechanism facilitated by gold, which involves the formation of electronrich Au species (Au delta-) and the development of Au-In alloys. This process improves the reducibility of nickel oxide while allowing a fraction of nickel to remain in its metallic form, managing a facile hydrogenation process and regulating the shift in selectivity from CH4 to CO.

}, keywords = {Alloy formation, Bimetallic catalyst, CO2 hydrogenation, RWGS, Selectivity switch, synergy, Trimetallic catalyst, XPS (X-ray photoelectron spectroscopy)}, issn = {1385-8947}, doi = {10.1016/j.cej.2025.165921}, author = {Bajpai, Jyotsna P. and Gupta, Sharad and Goud, Devender and Deka, Diku Raj and V. Jagtap, Anuradha and Kumar, Pawan and Ahamed, Momin and Peter, Sebastian C. and Vinod, C. P.} }