@article { ISI:000352488300022, title = {Activity enhancement upon the incorporation of titanium: au@ti-sio2 core-shell nanocatalysts for the CO oxidation reaction}, journal = {ChemCatChem}, volume = {7}, number = {7}, year = {2015}, month = {APR}, pages = {1222-1230}, publisher = {WILEY-V C H VERLAG GMBH}, address = {BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY}, abstract = {

The encapsulation of gold nanoparticles 8-12nm in size within a porous Ti-SiO2 shell to form a core-shell nanoarchitecture was investigated, and the catalytic activity of the resulting structure was probed. Detailed characterization of the synthesized materials shows that the core-shell morphology is lost beyond a certain amount of incorporated titanium, and results in normal gold-supported Ti-SiO2. The material has a high surface area (913m(2)g(-1)) and high porosity, both of which make it an excellent choice for catalytic applications. With the optimum amount of incorporated Ti, the core-shell catalyst shows excellent room-temperature CO oxidation activity over several cycles with retention of its morphology at higher temperatures.

}, keywords = {core-shell structures, gold nanoparticles, Oxidation, Ti-SiO2}, issn = {1867-3880}, doi = {10.1002/cctc.201402954}, author = {Sekhar, Anandakumari C. Sunil and Kottavarithottil Ziyad and Soni, Yogita and Vinod, Chathakudath 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 {45361, title = { One pot ligand exchange method for a highly stable Au-SBA-15 catalyst and its room temperature CO oxidation}, journal = {Chemical Communications}, volume = {54}, year = {2018}, month = {NOV}, pages = {12412-12415}, type = {Article}, abstract = {A modified deposition precipitation (DP) method has been developed to address a fundamental issue of supporting well dispersed Au nanoparticles on silica. Ammonium chloride (NH4Cl) plays an important role in in situ modifying the gold precursor (HAuCl(4)3H(2)O) solution allowing facile deposition of gold NPs in the channels of SBA-15. The Au-SBA-15 catalyst (2.8 wt\%) synthesized by this procedure showed 100\% conversion for CO oxidation at room temperature with excellent stability at room temperature and high temperature.}, issn = {1359-7345}, doi = {10.1039/c8cc06887a}, author = {Soni, Yogita and Kavya, I. and Ajithkumar, T. G. and Vinod, C. P.} } @article {46715, title = {Spectroscopic evidences for the size dependent generation of pd species responsible for the low temperature CO oxidation activity on Pd-SBA-15 nanocatalyst}, journal = {Applied Catalysis B-Environmental}, volume = {272}, year = {2020}, month = {SEP }, pages = {118934}, type = {Article}, abstract = {

A comprehensive size dependent CO oxidation activity has been demonstrated for Pd-SBA-15 catalysts with Pd NPs of varying sizes such as 1-2, 4-6 and 7-10 nm. Pd-SBA-15 catalyst with smallest sized NPs (Pd-S-N) has been synthesized by modified deposition precipitation method recently developed in our lab. Pd-S-N catalyst (reduced at 400 degrees C) demonstrated CO oxidation activity with lower light off temperature (50 degrees C), clearly one of the best reported for a Pd-silica system. A detailed XPS and in-situ DRIFTS analyses further supported by XAS and DFT calculations reveal the presence of easily decomposable highvalent Pd-oxide on co-ordinatively unsaturated Pd sites (Pdcus). Weak binding of CO on Pdcus sites in small Pd NPs leaving sites for oxygen activation is attributed to the low temperature activity of Pd-S-N for CO oxidation.

}, keywords = {CO oxidation, high-valent Pd species, Pd nanoparticles, SBA-15, under coordinated Pd atoms}, issn = {0926-3373}, doi = {10.1016/j.apcatb.2020.118934}, author = {Soni, Yogita and Pradhan, Sumanta and Bamnia, Mahesh K. and Yadav, A. K. and Jha, S. N. and Bhattacharyya, D. and Khan, Tuhin Suvra and Haider, M. A. and Vinod, C. P.} } @article {47634, title = {Role of metal-support interaction for atmospheric pressure CO2 hydrogenation over Pd/(Ti)-SBA-15 catalyst: effect of titanium composition on products selectivity}, journal = {Molecular Catalysis}, volume = {511}, year = {2021}, month = {JUL}, pages = {111732}, type = {Article}, abstract = {The potential role of metal-support interaction for tuning the product selectivity during atmospheric pressure CO2 hydrogenation has been demonstrated on Pd/(Ti)-SBA-15 catalyst. Highly dispersed Pd NPs on SBA-15 (Pd/ SBA-15) was synthesized and further modified with titanium of varying composition. Comparison of catalytic activity of Pd/Ti-SBA-15 with its counterparts (Pd/SBA-15 and Pd/TiO2) illustrated the significance of strong PdTi interface in this catalyst and its role in tuning the product selectivity of CO2 hydrogenation. The generation of an ample amount of oxygen vacancies in the Pd/Ti-SBA-15 catalyst with maximum metallic Pd sites in close vicinity of Ti is proposed to boost the CO2 hydrogenation activity.}, keywords = {CO2 hydrogenation, Metal-support interaction, Modified deposition precipitation, oxygen vacancies, Titanosilicates}, issn = {2468-8231}, doi = {10.1016/j.mcat.2021.111732}, author = {Soni, Yogita and Gupta, Sharad and Vinod, C. P.} }