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Catalytic Properties of Various Oxides and Mesoporous Materials Containing Niobium and Sulfate Ions, in the Oxidation Reaction of 1-Octanol  [PDF]
Alaa H. Hussein, Ahmad Khalil, Mohamad Jahjah, Mourtada Srour, Rabih Jahjah, Nicolas Duget, Marc Lemaire, Daoud Naoufal
International Journal of Organic Chemistry (IJOC) , 2018, DOI: 10.4236/ijoc.2018.81003
Abstract: Several types of solid acid catalysts were prepared based on oxides like (ZrO2, TiO2, HfO2, MCM-41 and SBA-15). Each catalyst was subjected separately to two types of impregnations: sulfate ions and niobium. The catalytic activity of these solids was tested in the oxidation reaction of 1-octanol. These catalysts showed acidic and redox characters. MCM-41 and SBA-15 materials showed higher redox catalytic activities through the formation of (octyl octanoate, peroxyacetal and octanal). Our interest was focused on obtaining the ester (octyl octanoate) with high yields.
Preparation and Catalytic Properties of Various Oxides and Mesoporous Materials Containing Niobium and Sulfate Ions, in the Etherification Reaction of 2-Naphtol  [PDF]
Alaa H. Hussein, Hiba Nahas, Mohamad Jahjah, Mourtada Srour, Rabih Jahjah, Nicolas Duget, Marc Lemaire, Daoud Naoufal
International Journal of Organic Chemistry (IJOC) , 2018, DOI: 10.4236/ijoc.2018.81002
Abstract: Several types of solid acid catalysts were prepared based on oxides like (ZrO2, TiO2, HfO2, MCM-41 and SBA-15), using two main preparation methods: the precipitation and the sol-gel methods. Each catalyst was subjected to two types of impregnations: sulfate ions using sulfuric acid as precursor and niobium using niobium oxalate as precursor. These prepared catalysts were tested in the etherification reaction of 2-naphtol, where the catalysts showed both acidic and redox properties. The acidic character was manifested through the formation of 2-butoxynaphtalene (with moderate yields) when oxide is sulfated, and the redox character (when impregnated with niobium) manifested through the formation of the interesting product 2-ethylnaphtofuran (with low yields) and other products that were a result of oxidative coupling of two 2-naphtol molecules (binol and acetal of binol). However despite the effort, several attempts to increase the yield of 2-ethylnaphtofuran did not work. All products prepared were obtained in pure form and characterized by 1H and 13C NMR, GC and MS.
Catalytic reduction of nitric oxide with carbon monoxide on copper-cobalt oxides supported on nano-titanium dioxide

CHEN Xi,ZHANG Junfeng,HUANG Yan,TONG Zhiquan,HUANG Ming,

环境科学学报(英文版) , 2009,
Abstract: A series of copper-cobalt oxides supported on nano-titanium dioxide were prepared for the reduction of nitric oxide with carbon monoxide and characterized using techniques such as XRD, BET and TPR. Catalyst CuCoOx/TiO2 with Cu/Co molar ratio of 1/2, Cu- Co total loading of 30% at the calcination temperature of 350°C formed CuCo2O4 spinel and had the highest activity. NO conversion reached 98.9% at 200°C. Mechanism of the reduction was also investigated, N2O was mainly yielded below 100°C, while N2 was produced instead at higher temperature. O2 was supposed to accelerate the reaction between NOx and CO for its oxidation of NO to give more easily reduced NO2, but the oxidation of CO by O2 to CO2 decreased the speed of the reaction greatly. Either SO2 or H2O had no adverse impact on the activity of NO reduction; however, in the presence of both SO2 and H2O, the catalyst deactivated quickly.
Progress of the Application of Mesoporous Silica-Supported Heteropolyacids in Heterogeneous Catalysis and Preparation of Nanostructured Metal Oxides  [PDF]
Yuanhang Ren,Bin Yue,Min Gu,Heyong He
Materials , 2010, DOI: 10.3390/ma3020764
Abstract: Mesoporous silica molecular sieves are a kind of unique catalyst support due to their large pore size and high surface area. Several methods have been developed to immobilize heteropolyacids (HPAs) inside the channels of these mesoporous silicas. The mesoporous silica-supported HPA materials have been widely used as recyclable catalysts in heterogeneous systems. They have shown high catalytic activities and shape selectivities in some reactions, compared to the parent HPAs in homogeneous systems. This review summarizes recent progress in the field of mesoporous silica-supported HPAs applied in the heterogeneous catalysis area and preparation of nanostructured metal oxides using HPAs as precursors and mesoporous silicas as hard templates.
Synthesis and Catalytic Performance of Mesoporous Material by Twostep Crystallization  [PDF]
LIU Wei-Qiao,SHANG Tong-Ming,LI Gong,WU Fei-Ke,TONG Hui-Juan,SUN Yu-Han
无机材料学报 , 2010, DOI: 10.3724/sp.j.1077.2010.00272
Abstract: A mesoporous material was synthesized by using the precursor of MCM22 zeolite through a twostep synthesis route, and characterized by XRD, N2 physical adsorptiondesorption, TEM, 27Al MAS NMR, IR spectra of pyridine adsorbed methods and so on. It was found that the synthesized sample was not a mixture of microporous zeolite and mesoporous material but a new mesoporous molecular sieve with strong acid sites and good thermal stability. The acid catalytic activity for macromolecules was evaluated and compared with conventional mesoporous material MCM-41 through the cracking reaction of cumene and alkylation reaction of benzene with 1dodecen. The results show that the conversions of cumene cracking at 350℃ over the new mesoporous material and MCM-41 are 68.98% and 48.80%, respectively. For the alkylation reaction of benzene with 1dodecen at 210℃, the conversions of 1dodecen over the new mesoporous materials and MCM-41 are around 95.20% and 86.89%, respectively. The selectivities of linear alkylbenzene over the new mesoporous materials and MCM-41 are around 88.11% and 90.06%, respectively. The results show that the catalytic property of the new mesoporous materials for macromolecules is superior to that of MCM-41.
Mesoporous SiO2-Supported Pt Nanoparticles for Catalytic Application  [PDF]
Yingze Cao,Wentao Zhai,Xiang Zhang,Shuxi Li,Lin Feng,Yen Wei
ISRN Nanomaterials , 2013, DOI: 10.1155/2013/745397
Abstract: SiO2 nanoparticles have been synthesized by combining Stober’s method and nonsurfactant process. The diameters and pore sizes can be controlled by altering the template and its concentration. Mesoporous SiO2 obtained this way has extremely large surface area compared with most oxide supports, which benefits the catalytic performance. Pt nanoparticles were in situ grown on and in mesoporous SiO2 nanoparticles with low amount of the metal and high load ratio. Furthermore, we firstly developed a novel route, called “one-pot” method, to prepare Pt/SiO2 catalyst where mesoporous silica preparing and Pt loading occurred in one step. This method is more efficient in saving reagent, since it can prevent Pt loss. In the meantime, it enables the template to reduce agent. The catalytic activity of Pt/SiO2 samples was measured by CO oxidation. It is indicated that the supporting silica with mesopores is more active than silica with micropores. 1. Introduction With the acceleration of industrialization and the increase of pollution, new catalysts development becomes very important. It is especially true when it comes to catalysts used to process gases from the incomplete combustion [1]. The incomplete combustion occurs in gasoline engine mainly discharges three kinds of harmful emissions: carbon monoxide (CO), unburned hydrocarbon emissions, and nitrogen oxides (NOx) [2]. With the establishment of stricter exhaust standards, together with the limit reserves and high cost of rare metals, preparing efficient catalyst with trace rare metals becomes the focus of study [3]. Three-way catalysis (TWC) which is a revolution can simultaneously converse the three major emissions into CO2, H2O, and N2. The active substance of TWC is usually made of Pt, Pd, and Rh loaded on oxide supporting [2]. Recently, many researches have been developed around oxide supporting such as ceria, zirconia, alumina, and composite ceria-zirconia supporting [4–11]. Silica has also been used for supporting noble metals. For example, mixed oxide catalysts silica-ceria have been prepared through coprecipitation after hydrothermal synthesis for reduction and oxygen storage. The noble metals were loaded after calcination of the supports. The catalyst was fairly active. The full CO oxidation conversion was about 400°C, and the calcination limited the oxygen storage [12]. Also the catalytic performances of noble metals supported on mesoporous silica MCM-41 were investigated for the hydrodesulfurization of benzothiophene. MCM-41 was made by the surfactant method and had been treated at a very high
Synthesis and catalytic applications of combined zeolitic/mesoporous materials  [cached]
Jarian Vernimmen,Vera Meynen,Pegie Cool
Beilstein Journal of Nanotechnology , 2011, DOI: 10.3762/bjnano.2.87
Abstract: In the last decade, research concerning nanoporous siliceous materials has been focused on mesoporous materials with intrinsic zeolitic features. These materials are thought to be superior, because they are able to combine (i) the enhanced diffusion and accessibility for larger molecules and viscous fluids typical of mesoporous materials with (ii) the remarkable stability, catalytic activity and selectivity of zeolites. This review gives an overview of the state of the art concerning combined zeolitic/mesoporous materials. Focus is put on the synthesis and the applications of the combined zeolitic/mesoporous materials. The different synthesis approaches and formation mechanisms leading to these materials are comprehensively discussed and compared. Moreover, Ti-containing nanoporous materials as redox catalysts are discussed to illustrate a potential implementation of combined zeolitic/mesoporous materials.
Preparation of Highly Dispersed Ni-Ce-Zr Oxides over Mesoporous γ-Alumina and Their Catalytic Properties for CO2 Methanation

- , 2016, DOI: 10.3866/PKU.WHXB201607291
Abstract: 采用柠檬酸(CA)-浸渍法制备了介孔γ-Al2O3(γ-MA)负载的高分散Ni-Ce-Zr氧化物,并将其用于二氧化碳甲烷化反应。研究了柠檬酸加入量对催化剂物理化学性质及催化性能的影响。结果表明,柠檬酸的加入可明显提高Ni-Ce-Zr氧化物在γ-Al2O3表面的分散性,同时可以增加镍氧化物与载体间的相互作用。制备材料经氢气还原后得到Ni-Ce-Zr/γ-MA催化剂,镍纳米颗粒均匀分散于γ-Al2O3表面。Ni-Ce-Zr/γ-MA催化剂在二氧化碳甲烷化反应中表现出了较高的反应活性和几乎100%的甲烷选择性。反应活性随CA/(Ni+Ce+Zr)摩尔比的增加而增加,主要是由于镍颗粒尺寸的减小和Ni-Ce-ZrOx物种电子和结构性质的提高。CA/(Ni+Ce+Zr)摩尔比为1的Ni-Ce-Zr/γ-MA催化剂在反应300 h内活性仅降低7%,并且没有明显积碳。表明催化剂在二氧化碳甲烷化反应中具有优异的反应稳定性和抗积碳性能。
Highly dispersed Ni-Ce-Zr mixed oxides supported on mesoporous γ-alumina (Ni-Ce-Zr/γ-MA) were prepared by a citric acid (CA)-assisted impregnation method and evaluated as catalysts for the methanation of CO2 with H2. The effects of the CA content of the reaction solution on the physicochemical properties and the catalytic performance of the Ni-Ce-Zr/γ-MA catalysts were investigated in detail. The addition of CA promoted the dispersion of the Ni-Ce-Zr oxide species on the γ-alumina surface and improved the interactions between the Ni oxide species and the support, resulting in the formation of homogeneously dispersed Ni nanoparticles in the γ-MA frameworks upon reduction with H2. The resulting Ni-Ce-Zr/γ-MA catalysts were highly active and showed almost 100% selectivity for CH4 during the methanation of CO2 at temperatures in the range of 150-400℃. Notably, the catalytic activity increased as the molar ratio of CA/(Ni+Ce+Zr) increased in the range of 0-2. This effect was most likely caused by the associated decrease in the Ni particle size and the improved electronic and structural properties of the Ni-Ce-ZrOx species. The results of a stability test for the Ni-Ce-Zr/γ-MA catalyst prepared with a CA/(Ni+Ce+Zr) molar ratio of 1.0 showed that there was only a 7% decrease in the CO2 conversion following a reaction time of 300 h at 300℃ with negligible coke deposition, indicating excellent catalytic stability and good anti-coking ability of these systems for the methanation of CO2
Complete catalytic oxidation of benzene on Co3O4 catalysts supported on mesoporous molecular sieves

Duan Minghu,Mu Zhen,Li Jinjun,Xie Qiang,

环境工程学报 , 2008,
Abstract: Co3O4 catalysts supported on various mesoporous molecular sieves, including MCM-41, MCM-48 and SBA-15, were prepared by incipient wetness impregnation method, and these catalysts were characterized by Nitrogen adsorption-desorption, XRD and TPR techniques. Then the influences of cobalt loading and mesoporous molecular sieves on the catalytic activity of catalysts in the complete oxidation of benzene were investigated. The results show that the activity of the catalyst with 20% Co3O4 loading was the best. Besides, the pore diameter of the supports and the reducibility of the catalysts play a key role, and the activity of the cobalt catalysts on different supports is in the following order: Co3O4/SBA-15> Co3O4/MCM-41> Co3O4/MCM-48.
Preparation of Mesoporous Silica Fibers in Porous Anodic Aluminum Oxide Template
WANG Wei, LI Xiao-Tian
无机材料学报 , 2010, DOI: 10.3724/sp.j.1077.2010.01277
Abstract: Mesoporous silica fibers were prepared within porous anodic aluminum oxide membrane (AAO) using a simple Sol-Gel method. The sample was characterized by SEM, XRD, nitrogen adsorption-desorption and TEM. The diameter and the length of the mesoporous silica fibers are depend on the pore diameter and thickness of AAO membrane, respectively. The orientation of the nanochannels in mesoporous silica fibers can be readily controlled by changing the aging environment. For the samples aged with the presence of water, all the nanochannels in the silica fibers are found to be circular around the fibers. However, for the samples aged without water, the nanochannels were found to be parallel along the fiber axes.
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