整体式Pt/γ-Al2O3/Ce0.5-xZr0.5-xMn2xO2催化剂低温催化燃烧饮食油烟

 采用固定床反应器评价了整体式催化剂 Pt/γ-Al2O3/Ce0.5-xZr0.5-xMn2xO2 去除饮食油烟的催化性能. 制备了一系列不同 Mn 含量的 Ce0.5-xZr0.5-xMn2xO2 储氧材料, 并考察了其作为载体对 Pt/γ-Al2O3/Ce0.5-xZr0.5-xMn2xO2 催化剂活性的影响. 应用 X 射线衍射 (XRD)、N2 物理吸附和 H2 程序升温还原 (H2-TPR) 等手段对催化剂进行了表征. XRD 结果表明, 贵金属 Pt 很好地分散在载体 γ-Al2O3 和 Ce0.5-xZr0.5-xMn2xO2 上. N2 物理吸附和 H2-TPR 研究结果与催化剂活性测试能很好吻合. 催化剂的活性顺序为 x = 0.10 > x = 0.15 > x = 0.05 > x = 0 > x = 0.20, Pt/γ-Al2O3/Ce0.4Zr0.4Mn0.2O2 催化剂活性最好, 油烟完全转化温度仅为 495 K.     

Pt/γ-Al2O3/CexZr1-xO2催化剂低温催化燃烧去除饮食油烟

以CexZr1-xO2固溶体做载体,制备了系列Pt/γ-Al2O3/CexZr1-xO2催化剂(x=1,0.75,0.5,0.25,0).应用Brunauer-Emmet-Teller(BET)比表面积分析、X射线衍射(XRD)和H2程序升温还原(H2-TPR)等手段对催化剂进行相关表征,并系统研究了催化剂在饮食油烟催化燃烧中的催化活性.BET结果表叫催化剂的比表面积随Ce/Zr摩尔比的减小而减小.XRD结果表明贵金属Pt很好地分散在氧化铝和CexZr1-xO2固溶体上.H2-TPR结果发现催化剂Pt/γ-Al2O3/Ce0.5Zr0.5O2的还原峰面积最大且氧离子的流动性最好.催化活性研究结果表明Pt负载在CexZr1-xO2固溶体上有利于油烟的催化燃烧,降低了反应温度.随着CexZr1-xO2固溶体中Ce/Zr摩尔比的变化,催化剂的活性顺序为Pt/γ-Al2O3/Ce0.5Zr0.5O2＞Pt/γ-Al2O3/Ce0.25Zr0.75O2＞Pt/γ-Al2O3/Ce0.75Zr0.25O2＞Pt/γ-Al2O3/CeO2＞Pt/γ-Al2O3/ZrO2.     

Pt/γ-Al2O3/CexZr1-xO2催化剂低温催化燃烧去除饮食油烟（英文）

以CexZr1-xO2固溶体做载体,制备了系列Pt/γ-Al2O3/CexZr1-xO2催化剂（x=1,0.75,0.5,0.25,0）.应用Brunauer-Emmet-Teller（BET）比表面积分析、X射线衍射（XRD）和H2程序升温还原（H2-TPR）等手段对催化剂进行相关表征,并系统研究了催化剂在饮食油烟催化燃烧中的催化活性.BET结果表明催化剂的比表面积随Ce/Zr摩尔比的减小而减小.XRD结果表明贵金属Pt很好地分散在氧化铝和CexZr1-xO2固溶体上.H2-TPR结果发现催化剂Pt/γ-Al2O3/Ce0.5Zr0.5O2的还原峰面积最大且氧离子的流动性最好.催化活性研究结果表明Pt负载在CexZr1-xO2固溶体上有利于油烟的催化燃烧,降低了反应温度.随着CexZr1-xO2固溶体中Ce/Zr摩尔比的变化,催化剂的活性顺序为Pt/γ-Al2O3/Ce0.5Zr0.5O2〉Pt/γ-Al2O3/Ce0.25Zr0.75O2〉Pt/γ-Al2O3/Ce0.75Zr0.25O2〉Pt/γ-Al2O3/CeO2〉Pt/γ-Al2O3/ZrO2.     

Pt/γ-Al2O3/CexZr1-xO2催化剂低温催化燃烧去除饮食油烟

以CexZr1-xO2固溶体做载体, 制备了系列Pt/γ-Al2O3/CexZr1-xO2催化剂(x=1, 0.75, 0.5, 0.25, 0). 应用Brunauer-Emmet-Teller (BET)比表面积分析、X射线衍射(XRD)和H2程序升温还原(H2-TPR)等手段对催化剂进行相关表征, 并系统研究了催化剂在饮食油烟催化燃烧中的催化活性. BET结果表明催化剂的比表面积随Ce/Zr摩尔比的减小而减小. XRD结果表明贵金属Pt很好地分散在氧化铝和CexZr1-xO2固溶体上. H2-TPR结果发现催化剂Pt/γ-Al2O3/Ce0.5Zr0.5O2的还原峰面积最大且氧离子的流动性最好. 催化活性研究结果表明Pt负载在CexZr1-xO2固溶体上有利于油烟的催化燃烧, 降低了反应温度. 随着CexZr1-xO2固溶体中Ce/Zr摩尔比的变化, 催化剂的活性顺序为Pt/γ-Al2O3/Ce0.5Zr0.5O2>Pt/γ-Al2O3/Ce0.25Zr0.75O2>Pt/γ-Al2O3/Ce0.75Zr0.25O2>Pt/γ-Al2O3/CeO2>Pt/γ-Al2O3/ZrO2.     

Ce0.45Zr0.45Y0.07La0.03O1.95/La-Ba-Al2O3质量比对整体式铁基催化剂上稀薄甲烷燃烧的影响

采用共沉淀法和胶溶法分别制备了高性能的储氧材料Ce0.45Zr0.45Y0.07La0.03O1.95(OSM)和耐高温高比表面的La-Ba-Al2O3,并以它们为载体,制备了一系列整体式铁基催化剂.考察了该系列催化剂对甲烷稀薄燃烧的催化性能.并用低温N2吸附-脱附,储氧量(OSC)测试,X射线衍射(XRD)和H2程序升温还原(H2-TPR)等测试手段考察了不同Ce0.45Zr0.45Y0.07La0.03O1.95/La-Ba-Al2O3质量比对催化剂特性的影响.活性测试结果表明,当Ce0.45Zr0.45Y0.07La0.03O1.95/La-Ba-Al2O3质量比为1:1时新鲜和老化催化剂的活性均最好,新鲜催化剂可在50000h-1的高空速条件下使含量为1%(体积分数)的甲烷在446℃起燃,553℃完全转化;低温氮气吸附-脱附测试结果和H2-TPR表明,不同的Ce0.45Zr0.45Y0.07La0.03O1.95/La-Ba-Al2O3质量比使催化剂表现出不同的织构性能和还原性能;XRD测试结果表明,OSM以均一固溶体存在,Fe高度分散在载体上.综合以上表征手段得出:合适的Ce0.45Zr0.45Y0.07La0.03O1.95/La-Ba-Al2O3质量比导致催化剂具有优异的稀薄甲烷催化燃烧活性和热稳定性.     

焙烧温度对 MnO2-CeO2/Zr0.25Ti0. 25Al0. 5O1.75 整体式催化剂 NH3 低温选择性催化还原 NO 性能的影响

 采用等体积浸渍法在不同温度下焙烧制备了一系列 MnO2-CeO2/Zr0.25Ti0.25Al0.5O1.75 整体式催化剂样品, 并用低温 N2 吸附-脱附、储氧量、X 射线衍射、X 射线光电子能谱和 NH3 程序升温脱附等对催化剂进行了表征, 考察了催化剂上 NH3 选择性催化还原 (SCR) NO 的活性. 结果表明, 随着焙烧温度的升高, 催化剂的比表面积和孔体积逐渐减小, 平均孔径逐渐增大, 储氧能力逐渐降低. 在 500~700 oC 焙烧时, 催化剂主要以无定形或微晶的形式存在; 在 500 oC 焙烧时, 催化剂表面 Mn 与载体之间的相互作用较强, 表面酸量最高, 有利于提高 SCR 活性. 尽管在 600 和 700 oC 焙烧的催化剂仍具有较高的 SCR 活性, 且表现出一定的抗 H2O 和 SO2 性能, 但活性有所下降. 800 oC 焙烧后催化剂的活性显著降低.     

具有低SO_2氧化活性的Pt/Zr_xTi_(1-x)O_2柴油车氧化催化剂的制备及性能

采用共沉淀法制备了一系列ZrxTi1-xO2(x=0.0,0.1,0.5,0.9,1.0)复合氧化物,并以此为载体,用等孔体积浸渍H2PtCl6制得Pt/ZrxTi1-xO2柴油车氧化催化剂.运用N2吸附-脱附,X射线多晶粉末衍射,X射线光电子能谱,H2程序升温还原和NH3程序升温脱附等手段对催化剂进行了表征.结果表明,在系列催化剂样品中,Zr0.1Ti0.9O2复合氧化物主要以锐钛矿形式存在,具有较好的织构性能,样品的比表面积达94m2/g,孔体积为0.33cm3/g.相应地,Pt/Zr0.1Ti0.9O2催化剂表现出优异的催化氧化性能,HC和CO的起燃温度(T50)分别为185和174oC,完全转化温度(T90)分别为197和201oC;且具有较低的SO2氧化活性,350oC时SO2仅转化25.5%.     

CO2 在高分散 Ni/La2O3 催化剂上的甲烷化

 以 La2O3 为载体, 采用浸渍法制备了 10%Ni/La2O3 催化剂, 考察了该催化剂的 CO2 甲烷化反应性能. 结果表明, 在较低的温度 (350 oC) 和高空速 (约 30000 h–1) 下, 甲烷时空收率可大于 3000 g/(kg•h), 无论转化率高低, 甲烷选择性始终保持在 100%. X 射线衍射和 H2-程序升温还原等表征结果表明, CO2 在 Ni/La2O3 催化剂上的加氢机理可能与 Ni/γ-Al2O3 上不同, 并且 La2O2CO3 的形成有利于提高催化剂活性.     

LaAl1-xFexO3/Al2O3/FeCrAl催化剂的制备及其对甲烷燃烧的催化性能

 以FeCrAl合金薄片为载体,以LaAl1-xFexO3为活性组分,以Al2O3为过渡层,制备了LaAl1-xFexO3/Al2O3/FeCrAl金属基整体式催化剂,并用XRD和SEM等方法对催化剂的物相和形貌进行了表征,对催化剂上甲烷催化燃烧活性进行了评价. 结果表明,催化剂物相中有LaAl1-xFexO3型钙钛矿及 α-Al2O3 和 γ-Al2O3; 催化剂的颗粒小于2 μm, 并且颗粒的尺寸及形貌与LaAl1-xFexO3中的Fe/Al摩尔比有关; 催化剂样品对甲烷催化燃烧活性的大小顺序为LaAl0.3Fe0.7O3/Al2O3/FeCrAl＞LaFeO3/Al2O3/FeCrAl＞LaAl0.5Fe0.5O3/Al2O3/FeCrAl＞LaAl0.7Fe0.3O3/Al2O3/FeCrAl＞LaAlO3/Al2O3/FeCrAl.     

铈基复合氧化物的结构及其对HCl催化氧化性能的影响

采用氨水共沉淀法制备了一系列铈基复合氧化物(Ce0.9M0.1O2,M=Cu、Cr、Zr、Ti、La),借助XRD、Raman、N2吸附-脱附、ESEM和H2-TPR等手段对复合氧化物的结构进行了表征,并考察了其在HCl催化氧化制Cl2过程中的性能.结果显示:Cu、Cr和Zr掺杂能显著减小复合氧化物晶粒尺寸,提高复合氧化物的比表面积和孔容,并提供更多的低温可还原氧物种.而La和Ti的掺杂可以获得较大的表面氧空位浓度以及增加高温可还原氧物种数目.复合氧化物结构和表面性质的变化显著影响了其HCl催化氧化活性,在430℃下铈基复合氧化物催化剂活性顺序为:Ce0.9Cu0.1O2Ce0.9Cr0.1O2Ce0.9Zr0.1O2Ce0.9Ti0.1O2Ce O2Ce0.9La0.1O2,低温可还原氧物种数目直接与催化剂活性有关.反应动力学测试显示催化剂低温可还原氧物种有利于HCl在催化剂表面的吸附和活化,而催化剂表面的氧空位可以促进氧分子的吸附和活化.     

N_2O在Cu_xFe_(1-x)Fe_2O_4和Ni_xFe_(1-x)Fe_2O_4复合氧化物催化剂上的分解反应

用共沉淀法制备了一组具有尖晶石结构的Cu-Fe和Ni-Fe复合氧化物,用于有氧条件下催化分解N2O,考察了催化剂组成对催化活性的影响.用N2物理吸附(BET)、X射线衍射(XRD)、H2程序升温还原(H2-TPR)等技术对催化剂进行了结构表征.结果表明:在不同组成的Cu-Fe、Ni-Fe系列复合氧化物催化剂中,Cu Fe2O4和Ni Fe2O4对于N2O分解反应的初活性较高,这是因为Cu Fe2O4和Ni Fe2O4的比表面积较高、晶粒较小,而且其表面氧物种与金属(Cu2+、Fe3+)的化学作用较弱,氧物种易脱除、脱氧量较高.相比较而言,Ni Fe2O4催化剂上的N2O分解活化能低于Cu Fe2O4,Ni Fe2O4的初活性优于Cu Fe2O4.500℃连续反应100 h,Cu Fe2O4上的N2O转化率降至84.9%,而Ni Fe2O4上的N2O转化率一直保持99%,Ni Fe2O4有较高的催化稳定性.     

V2O5-Sb2O3-TiO2催化剂 低温NH3还原NO及其抗H2O和SO2毒化性能

浸渍法制备了催化剂V₂O₅-Sb₂O₃-TiO₂,考察了V₂O₅、Sb₂O₃负载量、pH值和焙烧温度对催化剂V₂O₅- Sb₂O₃-TiO₂低温氨选择性催化还原(SCR)NO活性的影响;同时,考察了催化剂V₂O₅-Sb₂O₃-TiO₂抗H₂O和SO₂毒化性能。结果表明,V₂O₅和Sb₂O₃负载量分别为5%和2%、焙烧温度为400℃、pH值为4时,催化剂SCR活性最好,反应温度220℃时,可达97%。Sb₂O₃的加入不仅能增强V₂O₅/TiO₂的催化活性,而且能明显提高催化剂的抗H₂O和SO₂毒化性能。SO₂、NO吸附暂态反应和TG-DTG测试表明,Sb₂O₃的促进机制主要是促进了催化剂在SO₂存在条件下对NO的吸附,同时,减弱了硫酸铵盐与催化剂之间的相互作用,硫酸铵盐更容易分解。     

Gas Phase Selective Catalytic Oxidation of Toluene to Benzaldehyde on V2O5-Ag2O／η-Al2O3 Catalyst

Gas phase selective catalytic oxidation of toluene to benzaldehyde was studied on V2O5-Ag2O/η-Al2O3 catalyst prepared by impregnation. The catalyst was characterized by XRD, XPS, TEM,and FT-IR. The catalytic results showed that toluene conversion and selectivity for benzaldehyde on catalyst sample No.4 (V/(V Ag)=0.68) was higher than other catalysts with different V/Ag ratios. This was attributed to the higher surface area, larger pore volume and pore diameter of the catalyst sample No.4 than the other catalysts. The XRD patterns recorded from the catalyst before and after the oxidation reaction revealed that the new phases were developed, and this suggested that silver had entered the vanadium lattice. XPS results showed that the vanadium on the surface of No.4 and No.5 sample was more than that in the bulk, thus forming a vanadium rich layer on the surface. It was noted that when the catalyst was doped by potassium promoter, the toluene conversion and selectivity for benzalde hydewere higher than those on the undoped catalyst. This was attributed to the disordered structure of V2O5 lattice of the K-doped catalyst and a better interfacial contact between the particles.     

Partial hydrogenation of adiponitrile to 6-aminocapronitrile over Ni/α-Al_2O_3 catalyst promoted with K_2O and La_2O_3

A novel K2O and La2O3 promoted nickel catalyst supported on a-Al2O3 was prepared by co-impregnation method, and it exhibited higher activity and 6-aminocapronitrile selectivity than Ni/a-Al2O3 during the hydrogenation of adiponitrile in the absence of ammonia, i.e., K2O and La2O3 improved the performance of the nickel-based catalyst.     

Gas Phase Selective Catalytic Oxidation of Toluene to Benzaldehyde on V2O5-Ag2O/η-Al2O3 Catalyst

Gas phase selective catalytic oxidation of toluene to benzaldehyde was studied on V2O5-Ag2O/η-Al2O3 catalyst prepared by impregnation. The catalyst was characterized by XRD, XPS, TEM,and FT-IR. The catalytic results showed that toluene conversion and selectivity for benzaldehyde on catalyst sample No.4 (V/(V Ag)=0.68) was higher than other catalysts with different V/Ag ratios. This was attributed to the higher surface area, larger pore volume and pore diameter of the catalyst sample No.4 than the other catalysts. The XRD patterns recorded from the catalyst before and after the oxidation reaction revealed that the new phases were developed, and this suggested that silver had entered the vanadium lattice. XPS results showed that the vanadium on the surface of No.4 and No.5 sample was more than that in the bulk, thus forming a vanadium rich layer on the surface. It was noted that when the catalyst was doped by potassium promoter, the toluene conversion and selectivity for benzaldehyde were higher than those on the undoped catalyst. This was attributed to the disordered structure of V2O5 lattice of the K-doped catalyst and a better interfacial contact between the particles.     

Comparative Study of CuO Species on CuO/Al2O3, CuO/CeO-Al2O3 andCuO/La2O-Al2O3 Catalysts for CO Oxidation

CuO/Al2O3, CuO/CeO2-Al2O3, and CuO/La2O3-Al2O3 (denoted as Cu/Al, Cu/CeAl, and Cu/LaAl) catalysts were prepared by an impregnation method. CuO species and CuO/Al2O3 thermal solid-solid interaction were characterized by in situ XRD, Raman spectroscopy and H2-TPR techniques. For the Cu/Al catalyst, a CuAl2O4 phase exists between the CuO and Al2O3 layer and the CuO phase exists on the surface in both highly dispersed and bulk forms. For the Cu/CeAl catalyst, there is highly dispersed and bulk CuO on the surface, but most of the CuO has transferred into the internal layer of CeO2 as bulk CuO and CuAl2O4. For the Cu/LaAl catalyst, only bulk CuO is present on the surface of the catalyst and no CuAl2O4 is formed. The catalytic activity order for CO oxidation is Cu/CeAl>Cu/Al>Cu/LaAl. The highly dispersed CuO on the catalyst surface may be the active phase for CO oxidation. The results show that the addition of CeO2 not only promotes both the transference of CuO and the formation of CuAl2O4 but also favors the CO oxidation due to the association of highly dispersed CuO with CeO2, while La2O3 hinders the transference of CuO and the formation of CuAl2O4.     

Study of The Pd-B/ γ-Al2O3 Amorphous Alloy Catalyst

The Pd-B/γ-Al2O3 amorphous alloy catalyst and Pd/γ-Al2O3 crystalline metal catalyst were prepared by KBH4 reduction and routine impregnation,respectively.Pd-B/γ-Al2O3 and Pd/γ-Al2O3 catalysts were characterized by XRD and SEM.It was found that the catalytic activity of the Pd-B/γ-Al2O3 amorphous alloy catalyst was higher than that of the Pd/γ-Al2O3 crystalline metal catalyst in the anthraquinone hydrogenation.     

用醇还原VOPO4·2H2O制备的VOHPO4·0.5H2O的择优取向性能

 研究了用醇还原VOPO4·2H2O制备的VOHPO4·0．5H2O的晶面择优\r\n取向现象及其在正丁烷和空气混合气体中活化后,产物（VO）2P2O7的\r\n晶面择优暴露对正丁烷氧化制顺酐性能的影响．以伯醇还原VOPO4·2H\r\n2O制备的VOHPO4·0．5H2O晶体,晶面择优取向于（220）面,晶型为玫\r\n瑰状或扭曲的片状聚集体;活化后的产物仅含（VO）2P2O7相,其（02\r\n0）晶面择优暴露．以仲醇还原VOPO4·2H2O制备的VOHPO4·0．5H2O晶\r\n体,晶面择优取向于（001）面,晶型为平板片状体;活化后的产物由\r\n（VO）2P2O7,VOPO4和无定形相组成,其中（VO）2P2O7相含量低,其\r\n（020）晶面暴露少．由苄醇、环己醇和3－甲基－3庚醇还原VOPO4·2\r\nH2O制备的VOHPO4·0．5H2O的XRD谱与用仲醇制备的相似．用一般方法\r\n（V2O5／异丁醇／H3PO4）制备的VOHPO4·0．5H2O晶体不具有晶面择优\r\n取向性质,活化后得到的（VO）2P2O7的结晶度较低．由正辛醇还原VO\r\nPO4·2H2O制备的VOHPO4·0．5H2O经活化后,对正丁烷氧化制顺酐的催\r\n化性能优于用仲辛醇和一般方法制备的VOHPO4·0．5H2O．     

ESR Characterization and Activity of V_2O_5/γ-Al_2O_3 Catalysts for Dehydrogenation of Isobutane

IntroductionIsobutene is the raw material for theproduction of many important chemicals.Thedehydrogenation of isobutane to isobutene oncatalysts Cr2 O3/γ- Al2 O3and Pt/γ- Al2 O3have beenextensively studied and successfully applied inindustry[1,2 ] .The dehydrogenation of isobutane to isobuteneis an endothermic reaction and is limited by thechemical equilibrium.Coke is easy formed on thecatalyst surface and the catalyst is frequentlyregenerated in the running.The oxidativedehydrogenation …     

Ni/Al2O3和Fe/Al2O3催化剂催化乙醇水蒸气重整制氢的对比研究

甲醇、乙醇等低碳醇催化重整制氢是燃料电池氢源的重要技术之一.乙醇和甲醇相比,更容易存储,低毒且可以从生物质经发酵获得[1,2].乙醇可以通过裂解、部分氧化、水蒸气重整和氧化重整等途径制氢[3~6].已有的文献表明,Pt、Ru、Rh、Pd等贵金属可有效地催化乙醇重整反应,载体多选用