Ji-Na Yan

A highly efficient heterogeneous catalytic system for Heck reactions with a palladium colloid layer reduced in situ in the channel of mesoporous silica materialsElectronic supplementary information (ESI) available: experimental details. See http://www.rsc.org/suppdata/cc/b4/b404916k/

A new catalyst, Pd-SBA, was prepared by the introduction of an Si-H function into the channel of SBA-15 mesoporous materials resulting in a highly dispersed metal colloid layer on the pore walls of the support material, creating one of the most active heterogeneous catalysts for Heck coupling reactions.

The preparation and photoluminescence properties of ZnO-MCM-41

Abstract ZnO crystallites have been anchored within the pore channels of silica MCM-41 (named ZnO-MCM-41) through a chelation method of Zn2+ by ethyldiamino group (EN) on the inner surface. The structural and elemental composition analyses of the material were characterized by the SAXRD, XRD, BET, XPS and EDS under HRTEM techniques. The ZnO crystallites were about 1.7 nm estimated from the UV–Vis spectra. The bright UV (377 nm), violet (420 nm) and blue–green (480 nm) photoluminescence (PL) bands have been detected. The unfamiliar violet PL band is related to the oxygen vacancies on the ZnO–SiO2 interface traps.

Effect of inorganic salt addition during synthesis on pore structure and hydrothermal stability of mesoporous silica

Abstract Mesoporous materials were synthesized without and with the addition of salts such as NaCl and NH 4 Cl and were characterized using different analytical techniques. The hydrothermal stability was investigated by water treating these mesoporous materials at 373 K for various times in closed bottles. Addition of salts resulted in transformation of mesophase, which depends strongly on the kinds and concentration of salts added. When added with NaCl, the mesoporous materials experienced phase transformations in the sequence MCM-41→KIT-1→MCM-41→KIT-1→amorphous phase as the NaCl/surfactant molar ratio increased. However, addition of NH 4 Cl led to the formation of disordered mesoporous materials. Mesoporous materials with high hydrothermal stability could be prepared by addition of a suitable amount of salts and the materials maintained their initial mesoporous structure after hydrothermal treatment at 373 K for at least 120 h in closed bottles. For mesoporous materials without salt addition or with addition of salts with unsuitable molar ratios, mesopores would collapse and the pore size distribution became very large after hydrothermal treatment.

A new thioether functionalized organic–inorganic mesoporous composite as a highly selective and capacious Hg2+ adsorbent

A new thioether functionalized organic-inorganic ordered mesoporous composite as a highly selective and capacious Hg2+ adsorbent was synthesized by one-step co-condensation of (1,4)-bis(triethoxysilyl)propane tetrasufide (BTESPTS, (CH3CH2O)3Si(CH2)3S-S-S-S(CH2)3Si(OCH2CH3)3) and tetraethoxysilane (TEOS), with tri-block copolymer poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) EO20PO70EO20 as template.

One-step synthesis of hydrothermally stable cubic mesoporous aluminosilicates with a novel particle structure

Abstract Hydrothermally stable and highly ordered cubic mesoporous aluminosilicate has been successfully prepared by using a one-step synthesis route. It consists of introducing the zeolite primary building units into the walls of the material. The synthesized material was analyzed by XRD, N 2 adsorption–desorption, FT-IR, HRTEM and other techniques. The characterization results showed that the hydrothermal stability of the material was greatly improved, while the pore system remained highly ordered. The hydrothermal stability is believed to be related with a novel “core-shell” particle structure that formed during the assembling of aluminosilicate precursors with the surfactant molecules together with most zeolite primary building units into the shell.

Preparation and characteristics of the ordered porous zirconia containing cerium

Abstract Cerium-incorporated ordered porous zirconia materials have been prepared by the surfactant-assisted route and a post-grafting method. The X-ray powder diffraction, TEM, nitrogen adsorption and UV-Vis spectroscopy were adopted for the characterization of the synthesized materials. It is shown that small amount of cerium has been successfully incorporated into the framework of zirconia, and the surplus cerium can be dispersed into the pore channels, as well as onto the outer pore surface. The introduction of cerium may induce more shrinkage of the lattice of ZrO2 and decrease the order of pore arrangement of ZrO2. However, both the specific surface area and the ordering of pore structure were retained. This new material may be a potential catalyst.

Preparation and redox behavior of ordered porous zirconium oxide loaded with cerium

Abstract Cerium incorporated ordered porous zirconia materials have been prepared by the surfactant-assisted route and post-grafting method. The XRD patterns, TEM, nitrogen adsorption, and UV-Vis spectroscopy were adopted for the characterization of the synthesized materials. It was shown that small amount of cerium can be incorporated into the framework of ZrO2 at the cerium loading not higher than 4wt%, excess amount of cerium could exist as nano-crystalline ceria onto the pore outer surfaces. The introduction of cerium induced more shrinkage of the zirconium framework but both the specific surface area and the ordering of pore structure were retained. The H2-TPR measurement shows much more increased redox activity of the prepared mesoporous zirconia sample containing 10wt% ceria than that of the reference sample of Ce0.35Zro.65O2 prepared by the co-precipitation process.