Study on the Nanosized Amorphous Ru-Fe-B/ZrO_2 Alloy Catalyst for Benzene Selective Hydrogenation to Cyclohexene

新奇 nanosized 为到环己烯的苯选择加氢的非结晶的 Ru-Fe-B/ZrO2 合金催化剂被调查。这催化剂的优异性质被归因于 nanosize 和非结晶的特性的联合以及到它的组织上特性。另外，锌离子，在泥浆的 ZrO2 的内容，和催化剂的预告的处理的集中被发现在改进这项活动和催化剂的选择有效。给词调音：Ru-Fe-B/ZrO2 非结晶的催化剂；苯选择加氢；

苯加氢制环己烯的Ru-Fe/ZrO_2的制备及其性能

采用沉淀法制备了Ru-Fe/ZrO2催化剂,考察了Fe/Ru、Ru的不同负载量和沉淀温度等因素对催化剂性能的影响,并对催化剂的循环使用情况进行了研究。对催化剂进行性能测试,在苯的转化率为34.70%时,环己烯选择性可达77.52%。XRD表征显示催化剂为晶体特征,活性组分在载体表面高度分散。

苯选择加氢制环己烯Ru-Fe/ZrO_2催化剂的表征

采用沉淀法制备了Ru-Fe/ZrO2催化剂,通过X射线光电子能谱、BET比表面积测试法、H2程序升温还原和H2程序升温脱附等方法对其进行了表征。研究结果表明:催化剂表面的Ru物种以元素态形式存在,催化剂中有Fe2O3形式存在。Fe的引入,使催化剂平均孔径增大,比表面积明显减小,Ru-Fe/ZrO2催化剂不但吸附了更多氢气,且更有利于环己烯的脱附,从而有效地提高了选择性。在苯液相加氢制备环己烯的反应中,反应20 min时苯转化率为75.64%,环己烯的选择性为55.87%。

Preparation,characterization and catalytic properties of S_2O_8^(2-)/ZrO_2-CeO_2 solid superacid catalyst

A novel solid superacid catalyst S2O8^2-/ZrO2-CeO2 was prepared by a coprecipitation method and characterized by means of XRD FTIR, BET, TEM and DSC/TG analysis methods. The results indicated that incorporation of appropriate amounts of Ce into the catalyst was beneficial to the formation of sole tetragonal ZrO2 and effectively prevented from the formation of monoclinic ZrO〉 and restrained the loss of sulfated species. XRD revealed the presence of tetragonal Ce0.16Zr0.84O2phase in the case of S2O8^2-/ZrO2-CeO2 calcined above 500 ℃. Catalytic activities of S2O8^2-/ZrO2-CeO2 for the esterification of lactic acid with n-butanol was studied. The results showed that the optimum conditions were as follows： calcination temperature of the catalyst 600 ℃, n（lactic acid）：n（n-butyl alcohol）=1.0：3.0, w（S2O8^2-/ZrO2- CeO2）=12.0%, reaction temperature 145 ℃, and reaction time 2 h. The esterification efficiency of lactic acid was about 96.6%.

Selective catalytic methanation of CO in hydrogen-rich gases over Ni/ZrO_2 catalyst

Ni/ZrO2 catalysts were prepared by the incipient-wetness impregnation method and were investigated in activity and selectivity for the selective catalytic methanation of CO in hydrogen-rich gases with more than 20 vol% CO2. The result showed that Ni loadings significantly influenced the performance of Ni/ZrO2 catalyst. The 1.6 wt% Ni loading catalyst exhibited the highest catalytic activity among all the catalysts in the selective methanation of CO in hydrogen-rich gas. The outlet concentration of CO was less than 20 ppm with the hydrogen consumption below 7%, at a gas-hourly-space velocity as high as 10000 h-1 and a temperature range of 260 °C to 280 °C. The X-ray diffraction （XRD） and temperature programmed reduction （TPR） measurements showed that NiO was dispersed thoroughly on the surface of ZrO2 support if Ni loading was under 1.6 wt%. When Ni loading was increased to 3 wt% or above, the free bulk NiO species began to assemble, which was not favorable to increase the selectivity of the catalyst.

Highly selective CO methanation over amorphous Ni-Ru-B/ZrO_2 catalyst

Amorphous Ni-Ru-B/ZrO2 catalyst was prepared by the means of chemical reduction, and selective CO methanation as a strategy for CO removal in fuel processing applications was investigated over the amorphous Ni-Ru-B/ZrO2 catalyst. The result showed that, at the temperature of 210-230 ℃, the catalyst was shown to be capable of reducing CO in a hydrogen-rich reformate to less than 10 ppm, while keeping the CO2 conversion below 1.55% and the hydrogen consumption below 6.50%. ？2009 Xin Fa Dong. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

Catalytic combustion of methane over nano ZrO_2-supported copper-based catalysts

The nano ZrO2-supported copper-based catalysts for methane combustion were investigated by means of N2 adsorption, TEM, XRD, H2-TPR techniques and the test of methane oxidation. Two kinds of ZrO2 were used as support, one （ZrO2-1） was obtained from the commercial ZrO2 and the other （ZrO2-2） was issued from the thermal decomposition of zirconium nitrate. It was found that the CuO/ZrO2-2 catalyst was more active than CuO/ZrO2-1. N2 adsorption, H2-TPR and XRD measurements showed that larger surface area, better reduction property, presence of tetragonal ZrO2 and higher dispersion of active component for CuO/ZrO2-2 than that of CuO/ZrO2-1. These factors could be the dominating reasons for its higher activity for methane combustion.

Selective CO methanation over amorphous Ni-Ru-B/ZrO_2 catalyst for hydrogen-rich gas purification

Amorphous Ni-Ru-B/ZrO2 catalysts were prepared by chemical reduction method. The effects of Ni-Ru-B loading and Ru/Ni mole ratio on the catalytic performance for selective CO methanation from reformed fuel were studied, and the catalysts were characterized by BET, ICP, XRD and TPD. The results showed that Ru strongly affected the catalytic activity and selectivity by increasing the thermal stability of amorphous structure, promoting the dispersion of the catalyst particle, and intensifying the CO adsorption. For the catalysts with Ru/Ni mole ratio under 0.15, the CO methanation conversion and selectivity increased significantly with the increasing Ru/Ni mole ratio. Among all the catalysts investigated, the 30 wt% Ni-Ru-B loading amorphous Ni61Ru9B30/ZrO2 catalyst with 0.15 Ru/Ni mole ratio presented the best catalytic performance, over which higher than 99.9% of CO conversion was obtained in the temperature range of 230℃-250℃, and the CO2 conversion was kept under the level of 0.9%.

Hydrogen production by glycerol reforming in supercritical water over Ni/MgO-ZrO_2 catalyst

Nano ZrO2 and MgO-ZrO2 were prepared by a self-assembly route and were employed as the support for Ni catalysts used in hydrogen production from glycerol reforming in supercritical water （SCW）. The reforming experiments were conducted in a tubular fixed-bed flow reactor over a temperature range of 600-800 ℃. The influences of process variables such as temperature, contact time, and water to glycerol ratio on hydrogen yield were investigated and the catalysts were charactered by ICP, BET, XRD and SEM. The results showed that high hydrogen yield was obtained from glycerol by reforming in supercritical water over the Ni/MgO-ZrO2 catalysts in a short contact time. The MgO in the catalyst showed significant promotion effect for hydrogen production likely due to the formation of the alkaline active site. Even when the glycerol feed concentration was up to 45 wt%, glycerol was completely gasified and transfered to the gas products containing hydrogen, carbon dioxide, and methane along with small amounts of carbon monoxide. At a diluted feed concentration of 5 wt%, near theoretical yield of 7 mole of H2/mol of glycerol could be obtained.

γ-Al₂O₃Supported SO₄^2&#45/ZrO₂Solid Superacid Catalysts for n-Pentane Isomerization

A solid superacid catalyst Pt-SO42-/ZrO2-A12O3 for n-pentane isomerization, was prepared by incipient-wetness impregnation. Preparetion conditions, namely, calcination temperature, concentration of sulfuric acid solution used in impregnation and Al2O3 concentration, were varied to investigate the effects on catalytic performance of Pt-SO42-/ZrO2-A12O3. The results showed that the PtSZA catalyst exhibited excellent catalytic performance for n-pentane isomerization. Under optimized preparation conditions of calcination temperature of 650°C, reaction time for 3 h, concentration of sulfuric acid solution for 0.5 mol/L, 30% of Al2O3 concentration and 0.3% of Pt concentration, the n-pentane conversion and isopentane selectivity of Pt-SO42-/ZrO2-A12O3 could reach up to 62.17% and 91.60%, respectively.

ESR STUDY OF ZrO2 CATALYST

The intensity of the signal(g=1.974)resulted from Zr+ ion on the surface or ZrO2 catalyst, increased with the calcination temperature and time, but that or the signal (g=2.003)resulted from F+s centers (surface oxygen ion vacancies with a single trapped electron) decreased and finally disappeared at 550℃.

S_2O_8^(2-)/ZrO_2-Al_2O_3固体超强酸催化剂的研制与应用

A S 2O 2- 8/ZrO 2 Al 2O 3 type solid superacid catalyst was prepared from ZrOCl 2·8H 2O, AlCl 3· 6H 2O and (NH 4) 2S 2O 8 by coprecipitation, maceration and calcination processes. Their crystal structures and acidities were determined by XRD and Hammett method, respectively. The activity of the catalyst was studied as function of Al 2O 3 content, calcination temperature and time in the esterification of acetic acid with butanol, and a conversion of 96 5% was obtained. The catalyst gave also higher yields in syntheses of ketals and acetals: cyclohexanone ethylene ketal(86 2%), acetophenone ethylene ketal(78 5%), acetylacetic ester ketal(88 5%), benzaldehyde glycol acetal(76 3%). The chemical structures of the products were confirmed by IR spectra.

超细Cu-ZnO-ZrO_2催化剂上甲醇合成的TPSR和TPD研究

采用MS -TPSR和MS -TPD技术在不同粒度的超细Cu -ZnO -ZrO2 催化剂上考查了CO2 和CO加氢合成甲醇的反应过程和吸附活化特征。研究表明 ,CO2 和CO都可以直接加氢合成甲醇。在CO2 +H2 反应过程中 ,CO2是合成甲醇的主要碳源 ,但是在CO +H2 反应过程中 ,不但CO可以直接加氢合成甲醇 ,CO2 也可以通过水汽变换反应而参与甲醇的合成 ,因此也是CO加氢合成甲醇的碳源之一。催化剂的粒度大小直接影响反应活性 ,催化剂粒度越小 ,甲醇的收率越高 ;粒度大小还与CO的吸附活化状态有关 ,从而影响CO加氢合成甲醇的反应机理 ,当催化剂粒度很小时 ,CO倾向于通过水汽变换反应生成CO2 ,再由CO2 加氢合成甲醇 ,当催化剂颗粒较大时 ,CO易于直接加氢合成甲醇。

固体酸催化剂S_2O_8^(2-)/TiO_2-ZrO_2合成马来酸二辛酯

The preparation of peroxodisulfated zirconia titania(PSZT) solid super acid has been investigated as function of molar ratio of Ti to Zr, impregnation time, calcination time and temperature in esterification of maleic anhydride with n octanol. The highest yield of dioctyl maleate was 98 2% at the optimum reaction conditions.

SO_4^(2-)/ZrO_2固体超强酸催化剂上异丁烷与丁烯烷基化的研究

在固定床连续性微反活性评价装置上 ,考察了异丁烷与丁烯在SO4 2 - /ZrO2 系列固体超强酸催化剂上烷基化反应的活性和选择性 ,借助XRD、DTA、NH3-TPD等分析方法对SO4 2 - /ZrO2 催化剂的结构和性能进行了表征。结果表明 ,SO4 2 - /ZrO2 催化剂表面酸性位的强度与焙烧温度密切相关。同时 ,SO4 2 - /ZrO2 固体超强酸催化剂上的中强酸位是烷基化反应的主要活性位 ,但酸强度越高 ,其比活性越高 ,而目标产物三甲基戊烷选择性越低。SO4 2 - /ZrO2 催化剂的弱酸位有利于烯烃齐聚反应 ,强酸位有利于裂化反应 ,氢转移、异构化反应一般发生在中强酸位 ,与烷基化反应要求的酸性位很接近 ,烷基化反应酸强度控制在 -8 1～ -12

用于二乙醇胺催化氧化脱氢的Cu-ZrO_2催化剂的制备与表征

采用共沉淀法制备了二乙醇胺催化氧化脱氢生产亚氨基二乙酸二钠盐用的Cu -ZrO2 催化剂。考察了不同制备条件对催化剂催化氧化反应性能和催化剂结构的影响。实验结果表明 ,催化剂中和终止 pH值、Cu与Zr原子的量比以及焙烧温度是影响催化剂性能的主要因素。经TG、XRD和外观分析 ,优质催化剂其中间体铜锆氢氧化物外观呈现亮而脆的绿色、密度大于1 72g/cm3 、热失重温度范围为 15 0～ 5 30℃ 。

CuO/ZrO_2催化剂活性组分与载体相互作用的研究

用多种物理化学手段，对不同方法制备的在ＺｒＯ２上分散的氧化铜体系进行较细致的表征和比较，结果表明，从已晶化的ＺｒＯ２和Ｚｒ（ＯＨ）４出发制得的催化剂性能上存在明显差异，并发现ＺｒＯ２上分散的氧化铜由于相互作用而具有显著的易还原和表面氧易脱出的特性，从而导致ＣｕＯ／ＺｒＯ２催化剂体系具有高的ＣＯ氧化活性。

Fe助剂对Cu/ZrO_2甲醇水蒸气重整制氢催化剂的影响

利用XRD、TPR和EXAFS等手段 ,研究了Fe助剂对Cu Fe2 O3 ZrO2 催化剂物化特性的影响 ,同时研究了对甲醇水蒸气重整反应活性和选择性的影响。结果表明 ,Fe对Cu ZrO2 催化剂结构有一定的修饰作用。添加Fe助剂后 ,铜的分散度提高 ,催化剂的起始还原温度提前 ,还原温度区间缩短 ;同时甲醇水蒸气重整制氢反应催化活性上升 ,氢选择性提高 ,产物中CO含量降低 。

超细ZrO_2催化剂上合成甲醇和异丁醇

采用超临界干燥法制备ＺｒＯ２超细催化剂，用于合成气高选择性合成甲醇、异丁醇。考察了碱金属助剂、焙烧温度、焙烧时间、助剂Ｋ２Ｏ含量、成型压力及反应温度等对合成甲醇、异丁醇的影响。结果是浸渍２％Ｋ２Ｏ、经６００℃焙烧４ｈ后得到的催化剂可高选择性合成甲醇、异丁醇，在４２０℃、１０ＭＰａ、５０００ｈ－１条件下生成异丁醇的组成为１６．３１％（ｍａｓｓ），时空产率为８．９０ｍｌ／（ｈ·Ｌ）。

水蒸汽对Ni/CeO_2-ZrO_2-Al_2O_3催化剂上CO_2+CH_4重整反应的影响

用水热合成法制备了Ni/CeO2 ZrO2 Al2 O3 催化剂 .进行了添加和不添加水蒸汽的CH4 +CO2 催化重整反应 ,测试了活性和稳定性 ,测量了积碳量 ,并用XAFS手段测试了催化剂Ni的K吸收边 .结果表明 ,在反应过程中有CeAlO3 的生成 ,但积碳是无水蒸汽添加的反应活性降低的原因 .反应气中添加水蒸汽能够减少积碳 ,从而提高催化反应的稳定性 .由于碳原子插入Ni晶格 ,无水蒸汽反应后的最近邻Ni Ni配位数有较大幅度的减少 .添加了水蒸汽的反应 ,最近邻Ni Ni配位数比反应前减少幅度小 ,这主要是由于在反应气中添加水蒸汽减少了积碳 。