Effective Hydrogenation of p-Chloronitrobenzene over Iridium Nanoparticles Entrapped in Aluminum Oxy-Hydroxide under Mild Conditions

2014 ◽  
Vol 881-883 ◽  
pp. 267-270 ◽  
Author(s):  
Guang Yin Fan ◽  
Chun Zhang
Keyword(s):  
Hydrogen Bond ◽  
Selective Hydrogenation ◽  
Sol Gel ◽  
The Other ◽  
Hydrogenation Product ◽  
Hydroxyl Groups ◽  
Surface Hydroxyl ◽  
Iridium Nanoparticles ◽  
Mild Conditions ◽  
Surface Hydroxyl Groups

The Ir/AlO(OH) catalyst was prepared by sol-gel method and used for selective hydrogenation of p-chloronitrobenzene (p-CNB) to p-chloroniamine (p-CAN). The mechanism of p-CNB hydrogenation over the catalyst was discussed. The hydrogen bond between the surface hydroxyl groups of the catalyst and the nitrogen present in p-CNB facilitated the hydrogenation of nitro group. On the other hand, the formation of hydrogen bond between the hydrogenation product and water promotes the rapid desorption of the hydrogenation product on the surface of the catalyst. Thus the activity and selectivity were greatly promoted.

Cooperation between the surface hydroxyl groups of the support and organic additives in the highly selective hydrogenation of citral

2012 ◽  
Vol 445-446 ◽  
pp. 351-358 ◽  
Author(s):  
Hai-Jun Jiang ◽  
Hong-Bin Jiang ◽  
De-Ming Zhu ◽  
Xue-Li Zheng ◽  
Hai-Yan Fu ◽  
...  
Keyword(s):  
Selective Hydrogenation ◽  
Hydroxyl Groups ◽  
Organic Additives ◽  
Surface Hydroxyl ◽  
Surface Hydroxyl Groups

scholarly journals Effects of the Covalent Bonding Entrapment of Tetrapyrrole Macrocycles Inside Translucent Monolithic ZrO2 Xerogels

Nano Hybrids ◽  
2014 ◽  
Vol 7 ◽  
pp. 1-34 ◽  
Author(s):  
Eduardo Salas-Bañales ◽  
R. Iris Y. Quiroz-Segoviano ◽  
Fernando Rojas-González ◽  
Antonio Campero ◽  
Miguel A. García-Sánchez
Keyword(s):  
Sol Gel ◽  
Hydroxyl Groups ◽  
Stable Form ◽  
Silica Xerogels ◽  
Oh Groups ◽  
Surface Hydroxyl ◽  
Surface Hydroxyl Groups ◽  
Spectroscopic Characteristics ◽  
Hydrophilic Character ◽  
First Time

While searching for adequate sol-gel methodologies for successfully trapping in monomeric and stable form either porphyrins or phthalocyanines, inside translucent monolithic silica xerogels, it was discovered that the interactions of these trapped tetrapyrrole macrocycles with Si-OH surface groups inhibit or spoil the efficient display of physicochemical, especially optical, properties of the confined species. Consequently, we have developed strategies to keep the inserted macrocycle species as far as possible from these interferences by substituting the surface-OH groups foralkylorarylgroups or trapping these species inside alternative metal oxide networks, such as ZrO2, TiO2, and Al2O3. In the present manuscript, we present, for the first time to our knowledge, a methodology for preserving the spectroscopic characteristics of metal tetrasulfophthalocyanines and cobalt tetraphenylporphyrins trapped inside the pores of ZrO2xerogels. The results obtained are contrasting with analogous silica systems and demonstrate that, in ZrO2networks, the macrocyclic species remain trapped in stable and monomeric form while keeping their original spectroscopic characteristics in a better way than when captured inside silica systems. This outcome imply a lower hydrophilic character linked to the existence of a smaller amount of surface hydroxyl groups in ZrO2networks, if compared to analogous SiO2xerogel systems. The development and study of the possibility of trapping or fixing synthetic or natural tetrapyrrole macrocycles inside inorganic networks suggest the possibility of synthesizing hybrid solid systems suitable for important applications in technological areas such as optics, catalysis, sensoring and medicine

The synthesis and structure of silica-supported bis(h5-cyclopentadienyl)dichlorotitanium(IV) complexes

1986 ◽  
Vol 51 (7) ◽  
pp. 1430-1438 ◽  
Author(s):  
Alena Reissová ◽  
Zdeněk Bastl ◽  
Martin Čapka
Keyword(s):  
Free Surface ◽  
Hydroxyl Groups ◽  
Titanium Complex ◽  
Surface Hydroxyl ◽  
Surface Hydroxyl Groups ◽  
Free Hydroxyl ◽  
Cyclopentadienyl Anion

The title complexes have been obtained by functionalization of silica with cyclopentadienylsilanes of the type Rx(CH3)3 - xSi(CH2)nC5H5 (x = 1-3, n = 0, 1, 3), trimethylsilylation of free surface hydroxyl groups, transformation of the bonded cyclopentadienyl group to the cyclopentadienyl anion, followed by coordination of (h5-cyclopentadienyl)trichlorotitanium. The effects of single steps of the above immobilization on texture of the support, the number of free hydroxyl groups, the coverage of the surface by cyclopentadienyl groups and the degree of their utilization in anchoring the titanium complex have been investigated. ESCA study has shown that the above anchoring leads to formation of the silica-supported bis(h5-cyclopentadienyl)dichlorotitanium(IV) complex.

Controllable synthesis of phosphate-modified BiPO4 nanorods with high photocatalytic activity: surface hydroxyl groups concentrations effects

RSC Advances ◽  
2015 ◽  
Vol 5 (121) ◽  
pp. 99712-99721 ◽  
Author(s):  
Yan Li ◽  
Yawen Wang ◽  
Yu Huang ◽  
Junji Cao ◽  
Wingkei Ho ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Surface Modification ◽  
Photocatalytic Performance ◽  
High Photocatalytic Activity ◽  
Hydroxyl Groups ◽  
Controllable Synthesis ◽  
Surface Hydroxyl ◽  
Methylene Orange ◽  
Surface Hydroxyl Groups

Surface modification by phosphate efficiently improves the photocatalytic performance of BiPO4 for the degradation of methylene orange (MO), by enhancing the concentration of surface hydroxyl groups and improving its hydrophilicity.

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