@article { ISI:000382349600001, title = {Large trisoctahedral Au nanoparticles encapsulated inside porous silica catalyses CO oxidation at room temperature: probing the effect of encapsulation and the role of step atoms and interfaces}, journal = {Applied Catalysis A-General}, volume = {524}, year = {2016}, month = {AUG}, pages = {1-7}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

As envisaged, a synthesis strategy is reported for encapsulating high index faceted trisoctahedral Au nanoparticles inside porous silica to preserve nanoparticle size by preventing sintering. Further, to probe the role of interfaces an active metal oxide junction was created by decorating trisoctahedral (TOH) Au nanoparticle with nano oxides before silica encapsulation. The activity of these catalysts was tested for CO oxidation reaction. The reaction was found to be facile on these encapsulated large structured Au nanoparticles showing appreciable activity at room temperature compared to non encapsulated counterparts. Apart from preventing sintering, the improved activity is demonstrated due to the retention of morphology and thereby the active centres due to encapsulation. (C) 2016 Elsevier B.V. All rights reserved.

}, keywords = {Defect sites, Encapsulation, High index facets, Metal-oxide active perimeter, Trisoctahedral Au nanoparticles}, issn = {0926-860X}, doi = {10.1016/j.apcata.2016.05.023}, author = {Sreedhala, S. and Maheshwari, Shruti and Betsy, K. J. and Vinod, C. P.} } @article {44496, title = {Highly selective aqueous phase hydrogenation of phenols over nanostructured RuO2 on MCM-41 catalysts}, journal = {Nano-Structures \& Nano-Objects }, volume = {13}, year = {2018}, month = {FEB}, pages = {36-43}, abstract = {Selective aqueous phase hydrogenation of phenol as well as its derivatives is important for the synthesis of chemical intermediates which are crucial for the manufacture of high-tonnage commodities and a multitude of value added platform chemicals. Herein, we report a facile catalyst made of highly dispersed small RuO2 nanoparticles supported on mesoporous MCM-41 using one-pot approach. The optimal 5RuO2-MCM-41 catalyst with particle size 6-8 nm showed excellent activity and selectivity in aqueous phase hydrogenation of phenol and other functionalized substrates, which are building blocks of lignin, to corresponding cyclohexanol products without any additives. These catalysts showed better stability and can be reused several times without any significant drop in activity which proves the heterogeneity of the immobilized oxide catalyst.}, doi = {10.1016/j.nanoso.2017.11.004}, author = {Betsy, K. J. and Lazar, Anish and Vinod, C. P.} } @article {44217, title = {Ru(II)-functionalized SBA-15 as highly chemoselective, acid free and sustainable heterogeneous catalyst for acetalization of aldehydes and ketones}, journal = {Catalysis Communications}, volume = {104}, year = {2018}, month = {JAN}, pages = {62-66}, type = {Article}, abstract = {

Combining electron deficient Ru(II) coordination sites with organofunctionalized SBA-15, (L)Ru(Il)@SBA-15, result in a mild, neutral, water scavenger free and chemo-selective acetalization catalyst for cyclic/acyclic acetals. Vacant coordination sites of ruthenium in (L)Ru(II)@SBA-15 activates protecting groups as well as reactants simultaneously and restricts the reverse acetalization reaction. Synthesized (L)Ru(Il)@SBA-15 catalyst has been thoroughly characterized and act as competitive catalyst compared to conventional acid catalysts. (L) RuaD@SBA-15 performs high catalytic activity as well as selectivity within 20 min with high TOF. The catalyst can be recycled and reaction parameters are optimized.

}, keywords = {Acetalization reactions, Acid free, chemo-selective, heterogeneous catalyst, Reusable, Ru(II) immobilized SBA-15}, issn = {1566-7367}, doi = {10.1016/j.catcom.2017.10.016}, author = {Lazar, Anish and Betsy, K. J. and Vinod, C. P. and Singh, A. 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 {48723, title = {Pd nanoparticles supported on N-incorporated hybrid organosilica as an active and selective low-temperature phenol hydrogenation catalyst}, journal = {ACS Applied Nano Materials}, volume = {6}, year = {2023}, month = {JUN}, pages = {11500-11512}, type = {Article}, abstract = {

A heterogeneous Pd-NPMO hybrid-silicacatalyst is synthesized andits application for aqueous phase selective hydrogenation of phenolto cyclohexanone at near ambient temperature (40 degrees C) and underatmospheric hydrogen pressure is demonstrated. The homogeneously distributedPd nanoparticles on N-bridged hybrid mesoporous organosilica showedremarkable activity and selectivity for cyclohexanone compared tothe unmodified Pd-SBA-15 catalyst. Control experiments strongly claimthe role of nitrogen domains in the organic framework of hybrid silicasupport in stabilizing small Pd nanoparticles and possibly modifyingthe Pd sites responsible for catalysis to activate the substrate moleculesin water. The hybrid silica catalyst was stable and reused severaltimes without any significant drop-in activity, proving the heterogeneityof the bifunctional Pd catalyst. Based on the density functional theorystudy and experimental interventions, a possible reaction mechanismfor the low-temperature phenol hydrogenation explaining the role oforganic domains in the hybrid-silica framework is proposed.

}, keywords = {cyclohexanone, Hybrid silica, palladium nanoparticles, Periodic mesoporous organosilica, phenol hydrogenation}, doi = {10.1021/acsanm.3c01540}, author = {Betsy, K. J. and Bajpai, Priyam and Lazar, Anish and Vanka, Kumar and Vinod, C. P.} }