中孔分子筛负载AlCl_3催化α-蒎烯聚合

制备了中孔Al系和Zr系分子筛,用H2SO4和H3BO3处理中孔分子筛(MCM 41)分别得到强酸性SO2-3/Zr MCM 41中孔分子筛催化剂。XRD、FT IR及3/Al MCM 41及BO3-4/Al MCM 41、SO2-4/Zr MCM 41、BO3-Hammett指示剂测试结果表明:这些中孔分子筛具有一定的长程有序性,结晶较好;强酸基团已进入MCM 41骨架内部,并与骨架原子形成了化学键,从而产生强酸中心;H0值小于-12.76,具有超强酸性。以它们为载体,负载AlCl3制成复合催化剂,催化α 蒎烯聚合,考察了载体种类、负载量及溶剂极性对α 蒎烯聚合的影响。

HMS中孔骨架上嵌入Co活性中心的研究

采用过渡金属元素Co做嵌入的杂原子 ,在室温下合成了Co -HMS ,以XRD、FT -IR、SEM等对样品进行了表征 ,并对影响合成催化剂的因素及催化剂催化氧化性能作了初步考察 ,为Co

臭氧多相催化氧化预处理石油炼制污水

采用湿混捏法制备了Mn负载型中孔活性炭催化剂,并对催化剂试样进行N2吸附-脱附、TG和XRD表征,研究了臭氧多相催化氧化预处理石油炼制污水及其氧化机理。表征结果显示,催化剂制备过程中加入的Mn(NO3)2既生成了催化活性中心MnOx,又提高了催化剂的中孔率。污水预处理实验结果表明,添加5份Mn(质量份数)制备的Mn负载型中孔活性炭催化剂催化臭氧预处理石油炼制污水的效果最好,在污水预处理100 min后,COD去除率达到56.90%,五日生化需氧量与COD的比值为0.32,满足后续生化处理工艺的进水要求;污水中加入叔丁醇后导致污水的COD去除率明显降低,验证了臭氧多相催化氧化体系产生了羟基自由基,具有高级氧化技术的特征。

Cu/Ce-HMS的合成

XRD、FT IR及HRTEM等表征证实合成了Cu、Ce双元金属嵌入的HMS ,合成样品为球状纳米晶体 ,Cu、Ce双元金属的嵌入 ,使HMS的D1 0 0 面的X衍射特征吸收峰呈现宽化和低角位移趋势 ,Si-O四面体的骨架不对伸缩振动带 ( 1 0 82cm- 1 )因金属源和嵌入的金属元素不同 。

Catalytic Synthesis of Geranyl Propionate

[Objective] The aim was to explore the optimal conditions for the catalytic synthesis of geranyl propionate. [Method] The synthesis of mesoporous molecular sieves Al-MCM-41 was carried out in an open-vessel. The mesoporous structure of as-synthesized Al-MCM-41 was characterized by X-ray diffraction （XRD） pattern, Fourier transform infrared （FT-IR） spectrum, NH3-Temperature Programmed Desorption （TPD）, and N2 adsorption-desorption isotherms. The catalytic performances of Al-MCM-41 for the synthesis of geranyl propionate （GP） with geraniol and propionic acid as reagents also were investigated. [Result] The as-synthesized Al-MCM-41 possesses typical hexagonal mesoporous structure with high long-range order and crystalline degree. Based on the systematic investigation of reaction time, temperature, amount ratio of reagents and regeneration of catalyst, the optimum reaction conditions were obtained with molar ratio of geraniol to propionic acid of 1.0∶1.5, reaction temperature of 120 ℃ and reaction time of 8 h. The high GP selectivity of 70.01% with geraniol conversion of 40.01% was achieved under above optimum conditions. The catalyst inactivation can be observed after five catalytic cycles. The regeneration of inactivated catalyst with high activity and selectivity can be achieved by calcination treatment to remove the carbon deposition, which covers the acid site of catalyst. [Conclusion] The optimal conditions for the synthesis of geranyl propionate were obtained.

Phenol photocatalytic degradation over mesoporous TUD-1-supported chromium oxide-doped titania photocatalyst

Mesoporous Technische Universiteit Delft（TUD-1）-supported chromium oxide-doped titania（Cr-TiO2） was developed as a promising photocatalyst for phenol photodegradation under visible light irradiation.Low-angle X-ray diffraction and Fourier transform infrared spectroscopy results confirmed the amorphous and mesoporous silicate framework of TUD-1 in TUD-1-supported Cr-TiO2.The mesostructure of TUD-1 was further verified via N2 adsorption-desorption analysis,which showed a type-IV isotherm with a narrow average pore size distribution of 3.9 nm and high surface area of 490 m^2/g.Transmission electron microscopy analysis results indicated that TUD-1-supported Cr-TiO2 contained nanoparticles and porous channels.An increase in band gap energy was observed after loading Cr-TiO2 into TUD-1.Compared with that of unsupported Cr-TiO2,TUD-1-supported Cr-TiO2 showed higher photocatalytic activity for phenol degradation under visible light irradiation.The TUD-1 supported Cr-TiO2 photocatalyst with a Si/Ti molar ratio of 30 exhibited the highest photodegradation of phenol（82%） of the prepared samples.The photodegradation of phenol by the supported catalyst followed the Langmuir adsorption isotherm with first-order kinetics.

A highly stable and active mesoporous ruthenium catalyst for ammonia synthesis prepared by a RuCl_3/SiO_2-templated approach

Molecular nitrogen is relatively inert and the activation of its triple bond is full of challenges and of significance.Hence,searching for an efficiently heterogeneous catalyst with high stability and dispersion is one of the important targets of chemical technology.Here,we report a Ba‐K/Ru‐MC catalyst with Ru particle size of 1.5–2.5 nm semi‐embedded in a mesoporous C matrix and with dual promoters of Ba and K that exhibits a higher activity than the supported Ba‐Ru‐K/MC catalyst,although both have similar metal particle sizes for ammonia synthesis.Further,the Ba‐K/Ru‐MC catalyst is more active than commercial fused Fe catalysts and supported Ru catalysts.Characterization techniques such as high‐resolution transmission electron microscopy,N2 physisorption,CO chemisorption,and temperature‐programmed reduction suggest that the Ru nanoparticles have strong interactions with the C matrix in Ba‐K/Ru‐MC,which may facilitate electron transport better than supported nanoparticles.

Formation mechanism of highly dispersed semi-embedded ruthenium nanoparticles in porous carbon matrix determined by in situ temperature-programmed infrared spectroscopy

The carbonization process of a sucrose‐RuCl3/SBA‐15composite towards a Ru‐containing ordered mesoporous carbon(Ru‐OMC)catalyst was studied by in situ temperature‐programmed infrared spectroscopy to identify the stabilization role of organic carbon precursors during the formation of highly dispersed Ru nanoparticles.The results show that the formation of metal carbonyl species results in the formation of homogeneously distributed Ru nanoparticles,and the rigid silica support and carbon matrix around the Ru(CO)x complex can significantly avoid the sintering and agglomeration of Ru metal particles during elevated temperature thermal treatment.These results ultimately demonstrate that sucrose plays important roles in the formation of homogeneously distributed Ru nanoparticles in a porous carbon matrix.?2018,Dalian Institute of Chemical Physics,Chinese Academy of Sciences.Published by Elsevier B.V.All rights reserved.

Highly selective production of phenol from benzene over mesoporous silica-supported chromium catalyst:Role of response surface methodology in optimization of operating variables

A Cr/SBA-16 catalyst was prepared using Cr（NO3）3 as a precursor and mesoporous silica SBA-16 as a support via a simple impregnation method. The catalyst was characterized using wide-angle X-ray diffraction （XRD）, low-angle XRD, N2 adsorption-desorption, transmission electron microscopy, and ultraviolet-visible spectroscopy. The catalyst activity was investigated in the direct bydroxylation of benzene to phenol using H2O2 as the oxidant. Various operating variables, namely reaction temperature, reaction time, amount of H2O2, and catalyst dosage, were optimized using central composite design combined with response surface methodology （RSM）. The results showed that the correla- tion between the independent parameters and phenol yield was represented by a second-order polynomial model. The high correlation coefficient （R2）, i.e., 0.985, showed that the data predicted using RSM were in good agreement with the experimental results. The optimization results also showed that high selectivity for phenol was achieved at the optimized values of the operating variables： reaction temperature 324 K, reaction time 8 h, H2O2 content 3.28 mL, and catalyst dosage 0.09 g. This study showed that RSM was a reliable method for optimizing process variables for benzene hydroxylation to phenol.

MPS/CAS Partner Group on Nanotechnology in Catalysis

The first contact between Bao Xinhe and the Fritz Haber Institute (FHI) of the Max Planck Society goes back to 1989, when he was a Humboldt Scholarship holder in Germany. He worked at the FHI with Gerard Ertl on the surface and catalytic properties of Ag-cluster until 1995, when he returned to China and joined the Dalian Institute of Chemical Physics (DICP) under the Chinese Academy of Sciences. The cooperation with the FHI continued in 2000, when a Partner Group was established under the leadership of Robert Schlogl and Bao Xinhe.

On-line catalytic upgrading of biomass fast pyrolysis products

Pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) was employed to achieve fast pyrolysis of biomass and on-line analysis of the pyrolysis vapors. Four biomass materials (poplar wood, fir wood, cotton straw and rice husk) were pyrolyzed to reveal the difference among their products. Moreover, catalytic cracking of the pyrolysis vapors from cotton straw was performed by using five catalysts, including two microporous zeolites (HZSM-5 and HY) and three mesoporous catalysts (ZrO2&TiO2, SBA-15 and Al/SBA-15). The results showed that the distribution of the pyrolytic products from the four materials differed a little from each other, while catalytic cracking could significantly alter the pyrolytic products. Those important primary pyrolytic products such as levoglucosan, hydroxyacetaldehyde and 1-hydroxy-2-propanone were decreased greatly after catalysis. The two microporous zeolites were ef-fective to generate high yields of hydrocarbons, while the three mesoporous materials favored the formation of furan, furfural and other furan compounds, as well as acetic acid.

Block Copolymer-Templated BiFeO3 Nanoarchitectures Composed of Phase-Pure Crystallites Intermingled with a Continuous Mesoporosity： Effective Visible-Light Photocatalysts？

Herein is reported the soft-templating synthesis of visible-light photoactive bismuth ferrite （BiFeO3） nanoarchitectures in the form of thin fihns using a poly（ethylene-co-butylene）-block-poly（ethylene oxide） diblock copolymer as the structure-directing agent. We establish that （1） the self-assembled materials employed in this work are highly crystalline after annealing at 550 ℃ in air and that （2） neither the bismuth-poor Bi2Fe4O9 phase nor other impurity phases are formed. We further show that there is a distinct restructuring of the high quality cubic pore network of amorphous BiFeO3 during crystallization. This restructuring leads to films with a unique architecture that is composed of anisotropic crystallites intermingled with a continuous mesoporosity. While this article focuses on the characterization of these novel materials by electron microscopy, krypton physisorption, grazing incidence small-angle X-ray scattering, time-of-flight secondary ion mass spectrometry, X-ray photoelectron spectroscopy, UV-vis and Raman spectroscopy, we also examine the photocatalytic properties and show the benefits of the combination of mesoporosity and nanocrystallinity. Templated BiFeO3 thin films （25% porosity） with a direct optical band gap at 2.9 eV exhibit a catalytic activity for the degradation of rhodamine B much better than that of nontemplated samples. We attribute this improvement to the nanoscale porosity, which provides for more available active sites on the photocatalyst.