@article { ISI:000374920400016, title = {CO oxidation on large high-index faceted Pd nanostructures}, journal = {Journal of Catalysis}, volume = {337}, year = {2016}, month = {MAY}, pages = {138-144}, publisher = {ACADEMIC PRESS INC ELSEVIER SCIENCE}, address = {525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA}, abstract = {

The structure sensitivity of CO oxidation has been investigated on oxide-supported palladium nanoparticles of different morphologies. The reactivity of concave nanocubes and nanoflowers that expose {3 1 0} and {3 1 1} high-index facets showed a lower onset temperature for CO oxidation than Pd nanospheres of size around 6 nm. These concave nanocubes and nanoflowers were also found to catalyze the CO oxidation reaction more efficiently than simple cubes and spheres of similar size that exposed low-index facets. The enhanced activity of these nanoparticles compared with other morphologies are attributed to the presence of sites of under-coordination on the exposed high-index facets. The larger nanoparticles were also found to be more stable in the reaction environment. (C) 2016 Elsevier Inc. All rights reserved.

}, keywords = {CO oxidation, High-index facets, Pd nanoparticles, structure sensitivity}, issn = {0021-9517}, doi = {10.1016/j.jcat.2016.01.017}, author = {Sreedhala, S. and Sudheeshkumar, V. and Vinod, C. P.} } @article { ISI:000373408600014, title = {Correlating the role of hydrophilic/hydrophobic nature of Rh(I) and Ru(II) supported organosilica/silica catalysts in organotransformation reactions}, journal = {Applied Catalysis A-General}, volume = {513}, year = {2016}, month = {MAR}, pages = {138-146}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Highly reactive and hydrophobic triphenyl phosphine based rhodium(I) and ruthenium(II) organometallic complexes over benzene containing periodic mesoporous organosilica (PMOB) have been synthesized. This has been achieved by the immobilization of neat metal complexes like RhCl(PPh3)(3) [Wilkinson catalyst], RuHCl(CO)(PPh3)(3) and RuCl2(PPh3)(3) over aminofunctionalized PMOB to get RhCl(PPh3)(2)-PrNH2PMOB, RuHCl(CO)(PPh3)(2)-PrNH2PMOB and RuCl2(PPh3)(3)-PrNH2PMOB, respectively. The physico-chemical properties of the functionalized catalysts were analyzed by elemental analysis, ICP-OES, XRD, N-2 sorption analyses, FT-IR, solid state C-13 and Si-29 NMR spectra, XPS, SEM, TEM and contact angle measurements. The XRD and N-2 sorption analyses showed excellent textural properties with ordered mesoporous channel structure of all synthesized catalysts. The organic moieties anchored in PMOB were confirmed by C-13 CPMAS NMR and Fr-IR spectroscopy with Si-29 CPMAS NMR spectroscopy providing the information about the degree of functionalization of surface silanol groups with organic moiety. The Rh(I) and Ru(II) complexes supported on MCM-41/SBA-15/PMOE (ethane-PMO) were synthesized, and their catalytic activities in hydrogenation and sulfoxidation reactions were compared with Rh(I) and Ru(II) complexes supported on PMOB. The results show that PMOB based catalysts exhibit higher activities and selectivities than MCM-41/SBA-15/PMOB supported catalysts, neat homogeneous complexes and without catalyst. The better catalytic performance of PMOB based catalyst is attributed to the hydrophobic nature and high surface area of the PMOB support. The recycling studies of anchored catalysts show no major deactivation of the catalyst. (C) 2015 Elsevier B.V. All rights reserved.

}, keywords = {Heterogeneous catalysts, Hydrogenation and sulfoxidation, Hydrophobic, Periodic mesoporous organosilica}, issn = {0926-860X}, doi = {10.1016/j.apcata.2015.12.026}, author = {Lazar, Anish and George, Shoy C. and Jithesh, P. R. and Vinod, C. P. and Singh, A. P.} } @article {45738, title = {Convenient route for Au@Ti-SiO2 nanocatalyst synthesis and its application for room temperature CO oxidation}, journal = {Journal of Physical Chemistry C}, volume = {121}, year = {2017}, month = {MAR }, pages = {4946-4957}, type = {Article}, abstract = {

Small gold nanoparticles.of size less than 5 nm encapsulated inside titanium modified silica shell have been reported. Here, a modified sol-gel method, which is a one-step process, produces Au@Ti-SiO2 nanocatalyst with a good control of titanium loading. With a titanium loading of 0.9 and 2.2 wt \% in silica, unprecedented low temperature activity (full conversion) is observed for this catalyst for CO oxidation reaction compared to Au@SiO2 catalyst. A combination of optimum sized gold nanoparticles with a large amount of oxygen vacancies created due to Ti incorporation in silica matrix is considered to be the reason for this enhanced catalytic activity. The size of.gold nanoparticles is maintained even after high temperature pretreatments, which show the benefit of encapsulation. The effect of the various pretreatments on the catalytic activity has also been reported.

}, issn = {1932-7447}, doi = {10.1021/acs.jpcc.6b10202}, author = {Soni, Yogita and Kumar, Anumol Erumpukuthical Ashok and Nayak, Chandrani and Deepak, Francis Leonard and Vinod, C. P.} } @article {46688, title = {CO2 hydrogenation to formate by palladium nanoparticles supported on N-incorporated periodic mesoporous organosilica}, journal = {ACS Sustainable Chemistry \& Engineering}, volume = {8}, year = {2020}, month = {OCT }, pages = {14765-14774}, type = {Article}, abstract = {

Development of a heterogeneous catalyst capable of selective transformation of CO2 to valuable products still remains a challenge. In this article, we account for the surfactant-directed synthesis of a new framework-incorporated nitrogen-containing periodic mesoporous organosilica nanosphere (NPMO). A thoroughly characterized N-incorporated hybrid PMO was utilized as a platform for stabilizing well-dispersed and easily accessible Pd nanoparticles (Pd-NPMO) without using any stabilizing agents or expensive dendrimers. Further, this bifunctional hybrid catalyst has been demonstrated to heterogeneously catalyze aqueous phase CO2 hydrogenation (CO2/H-2 ratio 1:3) for the direct synthesis of formate under 4 MPa pressure and at 100 degrees C. To validate the superior performance of the Pd-NPMO catalyst, we compared the activity with Pd-SBA-15 catalysts, and the results showed a 10-fold increase in turnover frequency of 108 h(-1) using Pd on NPMO which envisaged the crucial role of nitrogen sites in this catalyst to boost the CO2 valorization to formate.

}, keywords = {CO2 hydrogenation, Formic acid synthesis, Hybrid silica, Pd nanoparticles, PMO}, issn = {2168-0485}, doi = {10.1021/acssuschemeng.0c03860}, author = {Betsy, K. J. and Lazar, Anish and Pavithran, Anjuna and Vinod, C. P.} } @article {47037, title = {Conductive interface promoted bifunctional oxygen reduction/evolution activity in an ultra-low precious metal based hybrid catalyst (vol 57, pg 1951, 2021)}, journal = {Chemical Communications}, volume = {57}, year = {2021}, month = {MAR }, pages = {2824}, type = {Correction}, issn = {1359-7345}, doi = {10.1039/d1cc90088a}, author = {Sarkar, Shreya and Varghese, Merin and Vinod, C. P. and Peter, Sebastian C.} } @article {47060, title = {Conductive interface promoted bifunctional oxygen reduction/evolution activity in an ultra-low precious metal based hybrid catalyst}, journal = {Chemical Communications}, volume = {57}, year = {2021}, month = {FEB}, pages = {1951-1954}, type = {Article}, abstract = {

Ultra low PtPd alloy deposited on Ni12P5 nanostructures (PtPd/Ni12P5) exhibited enhanced ORR activity (onset: 1.003 V and E-1/2:0.95 V) on par with commercial Pt/C and superior OER activity with 81\% reduction of the precious metal compared to the commercial catalyst.

}, issn = {1359-7345}, doi = {10.1039/d0cc08225b}, author = {Sarkar, Shreya and Varghese, Merin and Vinod, C. P. and Peter, Sebastian C.} } @article {47746, title = {CuO as a reactive and reusable reagent for the hydrogenation of nitroarenes}, journal = {Applied Catalysis B-Environmental}, volume = {297}, year = {2021}, month = {NOV}, pages = {120417}, type = {Article}, abstract = {{Copper oxide (CuO) is used as a reusable solid reagent for hydrogenation of nitroarenes to aminoarenes. The use of CuO resulted in 100 \% conversion of 2.9 mmol of nitrobenzene to aniline in 45 s at room temperature using hydrazine hydrate as the reducing agent. During the reaction, CuO is converted to inactive metallic Cu which can be regenerated to active CuO by thermal oxidation. DFT simulations indicated facile formation of oxygen vacancies (EO}, keywords = {Copper vacancy, CuO, Hydrogenation, Nitroarene reduction, Oxygen defects, Reactive solids}, issn = {0926-3373}, doi = {10.1016/j.apcatb.2021.120417}, author = {Rajendran, K. and Pandurangan, N. and Vinod, C. P. and Khan, Tuhin S. and Gupta, Shelaka and Haider, M. Ali and Jagadeesan, D.} } @article {48261, title = {Covalently interconnected layers in g-C3N4: toward high mechanical stability, catalytic efficiency and sustainability}, journal = {Applied Catalysis B: Environmental}, volume = {322}, year = {2023}, month = {MAR}, pages = {122069}, type = {Article}, abstract = {

The grim prospects for the industrial utilization of g-C3N4 nanosheets arise from multi-step processing resulting in low material yields and poor visible light response due to quantum confinement. Herein, we introduce a strategy for linking the adjacent layers of g-C3N4 covalently to realize a high surface area without excess mass loss in a one-step process by introducing diethylene glycol as a precursor that produces-(CH2)2-O-(CH2)2-linkers in-situ. Their presence increases interlayer spacing and introduces surface curvatures, discouraging the stacking of a larger number of layers to produce nanosheets with-3 times higher surface area. Interestingly, unlike other layered materials, the linkers also provide extraordinary mechanical stability against exfoliating forces. In addition, the process instills sub-bandgap states and a considerable visible light response at 500 nm to slow down the picosecond exciton recombination dynamics, resulting in-5 times enhancement in H2 generation efficiency from photocatalytic water-splitting over the bulk sample.

}, keywords = {Layer-linkers, Sustainable synthesis, Transient absorption spectroscopy, water-splitting}, issn = {0926-3373}, doi = {10.1016/j.apcatb.2022.122069}, author = {Roy, Raj Sekhar and Mondal, Sanjit and Mishra, Samita and Banoo, Maqsuma and Sahoo, Lipipuspa and Kumar, Amit and Vinod, C. P. and De, Arijit K. and Gautam, Ujjal K.} }