Physico-Chemical Properties of Cobalt–Ruthenium (10% Co–0.5% Ru) Catalysts Supported on Binary Oxides 8.5%ZrO<Subscript>2</Subscript>/Support (SiO<Subscript>2</Subscript>, Al<Subscript>2</Subscript>O<Subscript>3</Subscript>, TiO<Subscript>2</Subscript>) for Fischer-Tropsch Synthesis

The promotion of Fischer-Tropsch catalysts 10%Co/Al₂O₃, 10%Co/SiO₂, 10%Co/TiO₂ by 0.5% Ru and the modification of supports by 8.5 wt% ZrO₂ have been studied. The following properties: catalyst specific surface area as well as reducibility and dispersion of metallic phase were studied by different techniques: BET, TPR, and H₂ chemisorption. The modification of supports by non-reducible ZrO₂, results in a decrease of cobalt oxide reduction on Al₂O₃ and TiO₂ but not on SiO₂ supports. Additionally the enhancement of cobalt dispersion was found for all catalysts with ZrO₂ modified supports. The impact of Ru promotion is likely due to the stabilization of applied supports, prevention or blockage of interaction between surface Co species and support and an increase in cobalt oxide reducibility to the catalytically active metallic cobalt phase.     

活性炭负载钌基氨合成催化剂的制备

利用浸渍法制备了活性炭负载钌基氨合成催化剂,讨论了影响钌分散度与氨合成催化活性的若干因素. 研究发现,若活性炭载体具有较大的比表面和较好的孔结构将有利于活性组分的分散. 同时,在浸渍之前,样品需在100～200 ℃干燥6～8 h. 催化剂各组分浸渍后对载体的表面结构影响不同,实验发现,Ba的添加可能为Ru的分散提供了合适的表面,而K主要填充于载体中孔并和Ru充分接触,并为Ru提供电子.同时要控制母体钌水溶液的pH值,并选用合适的浸渍顺序,方能达到较好的效果.     

Preparation of three-dimensional ordered macroporous SiCN ceramic using sacrificing template method

Three-dimensional (3D) long range well ordered macroporous SiCN ceramics were prepared by infiltrating sacrificial colloidal silica templates with the low molecular weight preceramic polymer, polysilazane. This was followed by a thermal curing step, pyrolysis at 1250 °C in a N₂ atmosphere, and finally the removal of the templates by etching with dilute HF. The produced macroporous SiCN ceramics showed high BET surface areas (pore volume) in the range 455 m²/g (0.31 cm³/g)–250 m²/g (0.16 cm³/g) with the pore sizes of 98–578 nm, which could be tailored by controlling the sizes of the sacrificial silica spheres in the range 112–650 nm. The sphere-inversed macropores were interconnected by 50 ± 30 nm windows and 3–5 nm mesopores embedded in the porous SiCN ceramic frameworks, which resulted in a trimodal pore size distribution. The surface of the achieved porous SiCN ceramic was then modified by Pt–Ru nanoparticle depositing under mild chemical conditions.     

A Novel Method to Immobilize Ru Nanoparticles on SBA-15 Firmly by Ionic Liquid and Hydrogenation of Arene

A novel support of the Ru nanoparticles was achieved by combination of electrostatic force and coordination. The Ru catalyst was used as heterogeneous catalyst for hydrogenation of arene. This catalyst is very active for the hydrogenation of benzene to cyclohexane even under mild conditions. The TOF of this Ru catalyst is 85.3 mol mol⁻¹ h⁻¹ at 20 °C and 1.0 MPa for complete hydrogenation of benzene. The catalytic activity did not decrease after other five runs. The excellent performance of this catalyst demonstrated that there existed synergistic effects among 1,1,3,3-tetramethylguanidinium, mesoporous SBA-15, and Ru nanoparticles.     

Ru/C催化剂的制备及其在精细化工中的应用

综述了制备方法、钌前驱体种类和活性炭性质对Ru/C催化剂性能的影响,阐述了Ru/C催化剂在羰基加氢和芳环加氢反应中的具体应用,并对Ru/C催化剂的开发进行了展望。     

Investigation of various ionomer-coated carbon supports for direct methanol fuel cell applications

High-performance fuel cell electrodes require architectures that offer appropriate electrochemical and nanoscopic catalytic reaction zones. In this direction, ionomer (perfluoro sulfonic acid)-coated carbon supports were prepared by adopting a simple and cheap synthetic strategy to offer both electronic and protonic contacts to the catalyst particulates. Pt–Ru bimetallic anode catalysts were prepared on these modified carbon supports by a colloidal method. The role of surface area of carbon supports and the influence of ionomer content in them towards the catalytic activities of Pt–Ru catalysts has been probed by using three kinds of carbon black powders with different physical properties. Their electrocatalytic efficiencies toward methanol oxidation were scrutinized via half-cell measurements in cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy. Catalysts particulates dispersed on carbon supports coated with ionomer exhibited better performance than those on the plain carbon supports, owing to the reduced micropores and increased interfacial area between catalyst particles and ionomer. Plain and modified carbon (MC) supports were characterized by using FTIR, BET-PSD and TEM techniques. Physico-chemical characterizations of supported catalyst systems were done by using XRD and TEM.     

Hydrodechlorination of para-substituted chlorobenzenes over a ruthenium/carbon catalyst

The hydrodechlorination (HDC) of chlorobenzene (abbreviated as CLB) and seven types of para-substituted chlorobenzenes (para-amino, -methoxy, -methyl, -chloro, -trifluoromethyl, -acetyl and -cyano: abbreviated as CLAN, CLAS, CLTN, DCLB, CLTF, CLAP and CLBN, respectively) were performed over 5%-ruthenium/carbon (Ru/C) under a hydrogen pressure of 0.5–1.5 MPa at 523 K.In the HDC of these model compounds, except for CLAP and CLBN, reductive cleavage between the carbon and chlorine atoms took place and dechlorinated compounds were produced preferentially. In the reaction of CLAP and CLBN, on the other hand, hydrogenation and/or hydrogenolysis of the substituent coincided with the HDC and a wide variety of products was observed accompanying the HDC product.For the chlorobenzenes of the simple HDC, the HDC reaction rate constants decreased in the orders of CLAN  CLB ≈ CLTN ≈ CLAS and CLB > DCLB  CLTF, respectively.In the reaction of the chlorobenzenes of the electron-donating substituent, the reaction constant (ln k/k₀) has no relevance to the Hammett substituent constant (). In the case of the chlorobenzenes possessing the electron-withdrawing substituent, on the other hand, it was indicated that the electron-withdrawing substituent suppressed the HDC reactivity of chlorobenzenes, although no proportional relationship was observed between the reaction rate constant and the Hammett substituent constant.To explore the factors affecting the HDC reactivity, quantum calculation according to the DFT method (B3LYP/LANL2DZ) was applied to the “chlorobenzenes-Ru₁₀” complex. As a result of the calculation, chlorobenzenes were adsorbed through a chlorine atom on the edge atom of the Ru₁₀ cluster. The magnitude of the adsorption energy, moreover, decreased in the order of CLAN > CLAS ≈ CLB ≈ CLTN and CLB > DCLB > CLTF, respectively. These orders of adsorption energy are similar to that of the HDC reaction rate constant. It was concluded that adsorption energy is a useful parameter for the reactivity index of the HDC.     

Ir(III) and Ru(II) Complexes in Photoredox Catalysis and Photodynamic Therapy: A New Paradigm towards Anticancer Applications

Individually, photoredox catalysis (PC) and photodynamic therapy (PDT) are well-established concepts that have experienced a remarkable resurgence in recent years, leading to significant progress in organic synthesis for PC and clinical approval of anticancer drugs for PDT. But, very recently, new photoredox catalyst systems based on Ir(III) and Ru(II) complexes have garnered significant interest because they can simultaneously be used as PDT agents apart from their demonstrated PC activity. This highlight discusses the unique PC behavior of emerging Ir(III)- and Ru(II)-based systems while also examining their potential PDT activity in cancer treatment.     

Ag-Pd-5Ru-Gd四元系部分相图的700℃等温截面

在Ag Pd Gd ,Ag Pd Ru ,Ag Ru Gd和Pd Ru Gd三元系合金相图的基础上 ,采用X射线衍射 ,差热分析、扫描电镜和显微金相分析等方法研究了Ag Pd Ru Gd(x(Ru) =5 % ,x(Gd) <2 5 % )四元系相图的 70 0℃等温截面。结果表明 :该截面上包含有 2个单相区 ,即Pd(Ag)和Pd3 Gd ;4个两相区 ,即Pd(Ag) (Ru) ,Pd(Ag) Pd3 Gd ,(Ru) Ag51Gd14 ,(Ru) Pd3 Gd ;3个三相区 ,即Pd(Ag) Pd3 Gd (Ru) ,Pd(Ag) Ag51Gd14 (Ru) ,Pd3 Gd Ag51Gd14 (Ru) ;1个四相区 ,即Pd(Ag) Pd3 Gd Ag51Gd14 (Ru)。未发现新的四元中间相     

人工神经网络在古陶瓷研究中的应用

用人工神经网络算法,构建区分宋代汝瓷和民窑钧瓷的数学模型,该模型可以用于钧瓷的配方设计,判断实际生产中的钧瓷配方是否能产生分相。