@article { ISI:000304106900015,
	title = {Electrostatic grafting of a triphenylphosphine sulfonate on SBA-15: application in palladium catalyzed hydrogenation},
	journal = {Catalysis Science \& Technology},
	volume = {2},
	number = {6},
	year = {2012},
	month = {FEB},
	pages = {1188-1195},
	publisher = {ROYAL SOC CHEMISTRY},
	address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND},
	abstract = {<p>A novel strategy for the immobilization of a sulfonate functionalized triphenylphosphine ligand by ion-ion interactions on an imidazolium modified SBA-15 is presented. A support containing electrostatically grafted triphenylphosphine as the ligand was reacted with PdCl2( CNPh)(2) and the resulting hybrid material catalyzed olefin hydrogenation under mild conditions. The catalyst exhibits excellent activity, selectivity and stability and it can be reused for at least ten times without any loss of activity. An analogous but covalently grafted palladium system does not show any hydrogenation activity under the same conditions. TEM images of the used catalyst clearly prove the absence of palladium nanoparticles. Additionally, XPS investigations prove that palladium( 0) is formed and the phosphine is oxidized. By AAS no palladium contamination down to 0.5 X 10(-4) mmol could be detected in the products and further leaching tests verified the reaction to be truly heterogeneous. This concept of non-covalent immobilization guarantees a tight bonding of the catalytically active species to the surface in combination with a high mobility, which should be favorable for other catalyses, too.</p>},
	issn = {2044-4753},
	doi = {10.1039/c2cy00535b},
	author = {Wang, Lei and Dehe, Daniel and Philippi, Thomas and Seifert, Andreas and Ernst, Stefan and Zhou, Zhou and Hartmann, Martin and Taylor, Robin N. Klupp and Singh, Anand Pal and Jia, Mingjun and Thiel, Werner R.}
}
@article {48958,
	title = {Efficient olefin epoxidation with high turnover rates over ordered mesoporous silica nanoparticles with uniform manganese sites},
	journal = {Microporous and Mesoporous Materials },
	volume = {362},
	year = {2023},
	month = {DEC},
	type = {Journal Article},
	abstract = {<p>Olefin epoxidation has been studied over a series of mesoporous manganese silicate nanoparticles and tBuOOH. Partial substitution of Si by Mn in silica framework leads to highly dispersed, distorted Mn(III) sites, confirmed by various physicochemical analyses. High conversion and stable styrene oxide, stilbene oxide and epoxy cyclohexane yield have been achieved with MS75 with 1:1.5 ratio of olefin: oxidant. However, at faster reaction rates lower styrene oxide yield is observed at lower Mn-containing catalyst (MS100). High TON, TOF over manganese sites shows accessible monomeric Mn sites. Attributed to high reactant density at redox-active Mn silicate sites due to facile diffusion across shallow pore depth channels of nanoparticulate om-MSx and surface hydrophobic characteristics. The catalysts were found to be stable under recycling and filtration experiments. The excellent stability against leaching of active manganese species indicates stable sites and good textural properties in om-MSx, essential for extended activity.</p>
},
	keywords = {epoxidation, Manganese silicates, Mesoporous silica nanoparticles, Ordered mesoporous silica, pH adjustment},
	issn = {1387-1811},
	doi = {10.1016/j.micromeso.2023.112800},
	author = {Negi, Sanjay Singh and Khatri, Prateek and Singh, Anand Pal}
}
