Improved Ti-containing Mesoporous Silica Catalyst Synthesized by Using Anionic Surfactant as Co-template

Ti-containing mesoporous silica materials(Ti-MSs) with isolated tetrahedrally coordinated Ti species have been widely applied in bulk molecular catalysis. Herein, Ti-MSs were synthesized using anionic surfactant SDS as the co-template. The SDS molecular assembled structures can interact with silica species through the interface hydrogen bonds leading to the formation of mesoporous silica structure with compact Ti-O bonds, lower hydrophilicity and low template cost. The influence of adding SDS as the co-template on the oxidation of styrene with aqueous H_2O_2 as the oxidant was investigated. Ti-MSs using SDS as the co-template showed better catalytic performance as compared with mesoporous titanium silicate synthesized with CTAB serving as the sole template. Moreover, the Ti-MSs synthesized at a Ti/Si ratio of 0.005 demonstrated an optimized performance for styrene oxidation with styrene conversion improved by 14.8%, benzaldehyde selectivity improved by 13.7% and styrene oxide selectivity improved by 9.2% when the reaction time was 6 h.

MCM-41 Prepared with Ionic Liquid and Cethytrimethylammonium Bromide as Co-templates

The mesoporous molecular sieves MCM-41 were prepared using room tempera-ture ionic liquid （RTIL） synthesized in laboratory and cethytrimethylammonium bromide （CTAB） as compound templates for the first time. They were prepared under low aging temperature and short aging time. Via characterizing by XRD and nitrogen adsorption instrument, MCM-41 synthesized by this new method exhibited good crystal structure and narrow pore distribution. The following pre-paratory conditions was optimal： the molar ratio of RTIL to CTAB was 1.0∶1.0, aging at 80 ℃, for 40 h and calcined at 540 ℃. It is found that the acidified MCM-41 improves its activity as catalyst over the unmodified ones.

Synthesis and Theoretical Investigation of a New Hybrid Polymeric Iodoplumbate Based on Co-template:[(ipq)_2(pea)(Pb_3I_9)·DMF]_n

A new iodiplumbate polymer [（ipq）2（pea）（Pb3I9）-DMF]n 1 （ipq = N-（isopentyl）- quinolinium, pea = protonated ethylamine） was synthesized by self-assembly reaction of ipq·I, PbI2 with ethylamine and structurally characterized. 1 crystallizes in the triclinic system, space group P1 with α= 1.0731（4）, b = 1.2560（4）, c = 2.0785（7） nm, α = 96.378（5）, β= 91.132（2）, γ= 100.303（5）°, V= 2.7369（16） nm^3, Z= 2, Dc = 2.770 g/cm^3,μ = 14.307 mm^-1, F（000） = 2014, R = 0.0588 and wR = 0.1345. 1 features its hybrid structure concertedly templated by two kinds of organic cations, which exhibits interesting semiconductor property. In 1, the [Pb2I6]^2 n infinite chains shape the sketch of the title compound constructed from face-sharing of ideal and distorted PbI6 octahedra. Based on the crystal structure data, quantum chemistry calculation with DFT was used to reveal the electronic structure of 1.

Morphology-controlled synthesis of mesoporous silica with co-template of surfactant P123 and ionic liquid [Dmim]Cl

Mesoporous silicas with different morphologies have attracted great interest in the fields of catalysis,separation and so on. In this study, silica hollow tubes with ordered mesopores were synthesized via a novel sol-gel method with an ionic liquid 1-decyl-3-methylimidazolium chloride（[Dmim]Cl） and a nonionic surfactant P123（PEO_（20）PPO_（70）PEO_（20）） as the co-template. Comparatively, silica hollow spheres with disordered mesopores were synthesized with only [Dmim]Cl as the template. The template dosage is the key factor in controlling the morphology. The micelles assembly mechanism based on hydrogen bonding interactions is proposed to be responsible for the formation of the final silica morphology and mesostructure.

Synthesis,Structure and Adsorption of AlPO-21 Prepared by Co-template Method

The phase of AlPO-21 was hydrothermally synthesized in the reactant system of diethylamine-RB-Al_2O_3-P_2O_5-H_2O-C_2H_5OH. The crystals of AlPO-21 growing in this system crystallizes in monoclinic system,space group P2_1/n with a=0.8542(4) nm,b=1.7635(8) nm,c=0.9082(4) nm,β=108.234(5)°,V=1.2993(10) nm 3,Z=4,and the formula is [C_4H_ 10 NH_2] +~[Al_3P_3O_ 12 (OH)] -. The structure is resolved by the direct method and refined to R_1=0.0767 and wR_2=0.1627 based on 1719 observed reflections with I>2.0σ(I). An asymmetric unit consists of three PO_4 tetrahedra,one AlO_4 tetrahedron and two AlO_5 trigonal bipyramids. The framework is composed of 3-D uniform channels along [100],[001] and [101] with eight-membered oxygen ring windows. The powder sample of the MS was investigated with powder XRD,TG/DTG/DTA and the adsorption of water,methanol,n-hexane,ethylene,and ethane. The specific property for sieving molecules was observed on the adsorption isotherms,and proves the result of the single crystal structural analysis.