Autothermal reforming of methane over Ni catalysts supported over ZrO2-CeO2-Al2O3

Ni catalysts supported on Al2O3, ZrO2-Al2O3, CeO2-Al2O3 and ZrO2-CeO2-Al2O3 were prepared by coprecipitation method, and their catalytic performances for autothermal reforming of methane to hydrogen were investigated. The Ni-supported catalysts were characterized by XRD, TPR and XPS. The relationship between the structures and catalytic activities of the catalysts was discussed. The results showed that the catalytic activity and stability of the Ni/ZrO2-CeO2-Al2O3 catalyst was better than those of other catalysts with the highest CH4 conversion, H2/CO and H2/COx ratio at 750 ℃. The catalyst showed a little deactivation along the reaction time during its 72 h on stream with the mean deactivation rate of 0.08%/h. The catalytic performance of the Ni/ZrO2-CeO2-Al2O3 catalyst was also affected by reaction temperature, no2 ： nCH4 molar ratio and nH2O ： nCH4 molar ratio. TPR, XRD and XPS measurements indicated that the formation of ZrO2-CeO2 solid solution could improve the dispersion of NiO, and inhibit the formation of NiAl2O3, and thus significantly promoted the catalytic activity of the Ni/ZrO2-CeO2-Al2O3 catalyst.     

Synthesis of Ni2P promoted trimetallic NiMoW/γ-Al2O3 catalysts for diesel oil hydrotreatment

The Ni2P promoted and γ-Al2O3 supported NiMoW sulfide catalyst consisting of 4 wt% Mo, 22 wt% W, 2 wt% Ni and 2.5 wt% Ni2P was synthesized by a co-impregnation method. The catalysts were characterized by N2 adsorption-desorption, X-ray diffraction (XRD), diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy, NH3 temperature-programmed desorption (NH3-TPD) and transmission electron microscopy (TEM). The results showed that Ni2P, Ni, Mo and W species were highly dispersed over γ-Al2O3. The hydrodesulfurization (HDS) of dibenzothiophene (DBT) showed that the presence of Ni2P brought a strong promotional effect on the HDS activity, which was further confirmed by the HDS and hydrodenitrogenation (HDN) of diesel oil under industrial conditions. The enhancement in HDN activity and stability by Ni2P addition could be attributed more to the effect of new active sites of Ni2P than that of acidity modification. The as-prepared Ni2P-NiMoW/γ-Al2O3 catalyst showed better hydrotreating performance than NiMoW/γ-Al2O3 and commercial catalysts.     

Cs-Fe-Co-Bi-Mn-Mo复合氧化物选择性催化氧化异丁烯

Mixed oxide catalyst Cs0.1 Fe2Co6BiMnMo12 Ox was prepared by the interprecipitation method, then the catalyst was calcined at different temperature. Selective oxidation of isobutene was carried out in a fixed-bed reactor. The results showed that the catalyst has high catalytic activity. Under the optimum reaction conditions ( n(-C4^= ) : n(O2) = 1:2-1:4, space velocity = 180h^-1, T = 360℃ ), the yield of methacmlein and methacrylic reached 80%, 8 %,respectively. The total yields of liquid products( methacrolein, methacrylic acid and acetic acid) reached about 90%.     

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.     

Effect of Reaction Temperature and Pressure on the Metathesis Reaction between Ethene and 2-Butene to Propene on the WO3/Al2O3-HY Catalyst

Effect of reaction temperature and pressure on the metathesis reaction between ethene and 2-butene to propene was studied on the WO3/γ-Al2O3-HY catalyst. The activity is found to increase with elevated temperature and reaches a plateau at 150-240℃. After that, the activity undergoes a remarkable decrement at too high temperature. The effect of temperature is elucidated by the oxidation state of tungsten species. The evaluation results also indicate that the stability is dependent on this reaction parameter. Medium pressure (0.5-0.8 MPa) is favorable for stability, while atmospheric pressure or too high pressure (>1.0 MPa) deteriorates the stability. For explanation, UV Vis, FT-IR, O2-TPO, and TG techniques are used to characterize the spent catalysts.     

铂沉积对Ga2O3-SiO2纳米粒子光催化性能的提高（英文）

Ga2O3‐SiO2 nanoparticles were prepared by a sol‐gel method and Pt was then immobilized on their surface via photo‐assisted deposition (PAD). The produced samples were characterized using X‐ray diffraction (XRD), ultraviolet and visible spectroscopy, photoluminescence emission spectroscopy, and surface area measurements. The catalytic performances of the Ga2O3‐SiO2 and Pt/ Ga2O3‐SiO2 samples were evaluated for the degradation of cyanide using visible light. XRD and EDX results showed that the Pt was well dispersed within the Ga2O3‐SiO2 phase and was detected on the surface of the catalyst, which confirmed the successful loading of Pt ions by the PAD method. BET results revealed that the surface area of Ga2O3‐SiO2 was higher than that of Pt/Ga2O3‐SiO2 . 0.3 wt% Pt/Ga2O3‐SiO2 exhibited the highest photocatalytic activity for degradation of cyanide under visible light. The catalyst could be reused with no loss in activity for the first 10 cycles.     

Methanation of carbon dioxide on Ni/ZrO2-Al2O3 catalysts:Effects of ZrO2 promoter and preparation method of novel ZrO2-Al2O3 carrier

The novel nickel-based catalysts with a nickel content of 12 wt% were prepared with the zirconia-alumina composite as the supports. The new carriers, ZrO2 improved alumina, were synthesized by three methods, i.e., impregnation-precipitation, co-precipitation, and impregnation method. The catalytic properties of these catalysts were investigated in the methanation of carbon dioxide, and the samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscope (XPS), temperature-programmed reduction (TPR) and temperature-programmed desorption (TPD) techniques. The new catalysts showed higher catalytic activity and better stability than Ni/γ-Al2O3. Furthermore, as a support for new nickel catalyst, the ZrO2-Al2O3 composite prepared by the impregnation-precipitation method was more efficient than the other supports in the methanation of carbon dioxide. The highly dispersed zirconium oxide on the surface of γ-Al2O3 inhibited the formation of nickel aluminate-like phase, which was responsible for the better dispersion of Ni species and easier reduction of NiO species, leading to the enhanced catalytic performance of corresponding catalyst.     

Co-modified Pd/CeO2-ZrO2 catalysts for methanol decomposition

Pd/Ce0.8Zr0.2O2 catalysts modified by cobalt were prepared by a sequential impregnation method and characterized by X-ray powder diffraction(XRD), N2adsorption/desorption(Brunauer-Emmet-Teller), oxygen storage capacity(OSC), CO-chemisorption, H2-temperature-programmed reduction(H2-TPR) and X-ray photoelectron spectroscopy(XPS). The effect of Co on the performance of methanol decomposition was evaluated at a fixed-bed microreactor. The results showed that the addition of Co can improve the oxygen storage capacity of the catalyst and the dispersion of Pd. XPS results indicated that Pd was in a partly oxidized(Pdδ+, 1δ2) state and Co2+was present in Pd catalysts modified by Co. A 90% conversion of methanol was achieved at around 280°C over Pd-Co/Ce0.8Zr0.2O2 catalyst which was 20°C lower than that over Pd/Ce0.8Zr0.2O2, indicating that both Pdδ+and Co2+play an important role in improving the catalytic activity of methanol decomposition.     

Co-modified Pd/CeO_2-ZrO_2 catalysts for methanol decomposition

Pd/Ce0.8Zr0.2O2 catalysts modified by cobalt were prepared by a sequential impregnation method and characterized by X-ray powder diffraction(XRD), N2adsorption/desorption(Brunauer-Emmet-Teller), oxygen storage capacity(OSC), CO-chemisorption, H2-temperature-programmed reduction(H2-TPR) and X-ray photoelectron spectroscopy(XPS). The effect of Co on the performance of methanol decomposition was evaluated at a fixed-bed microreactor. The results showed that the addition of Co can improve the oxygen storage capacity of the catalyst and the dispersion of Pd. XPS results indicated that Pd was in a partly oxidized(Pdδ+, 1δ2) state and Co2+was present in Pd catalysts modified by Co. A 90% conversion of methanol was achieved at around 280°C over Pd-Co/Ce0.8Zr0.2O2 catalyst which was 20°C lower than that over Pd/Ce0.8Zr0.2O2, indicating that both Pdδ+and Co2+play an important role in improving the catalytic activity of methanol decomposition.     

Synthesis of Cu^Ⅱ/ZIF-8 Metal-organic Framework Catalyst and Its Application in the Aerobic Oxidation of Alcohols

The tliree-dimensional copper-doped zeolitic imidazolate framework ZIF-8(Cu^Ⅱ/ZIF-8) was prepared by a metal ion exchange process, using reaction of three different copper salts, zinc nitrate hexahydrate[Zn(NO)3·6H2O] and 2?methylimidazole(2-MelM) under nitrogen atmosphere at the room temperature. The TEM and PXRD results indicated that the morphology of Cu^Ⅱ/ZIF-8 was rhombic dodecahedron and the structure was intact after copper was doped into the porous ZIF-8. The synthesized Cu(NO3)2/ZIF-8 heterogeneous catalyst showed an excellent activity for tlie aerobic oxidation of primary alcohols employing molecular oxygen as oxidant. Moreover, tlie Cu(NO3)2/ZIF-8 heterogeneous catalyst can cycled 15 times without leaching of copper.     

Preparation, Characterization and Catalytic Properties of S2O2-8/ZrO2 Supported by Tungsten Carbide

A WC-supported S2O2-8/ZrO2(PSZ) catalyst was prepared and characterized by means of XRD, BET, FTIR and XPS. The isomerization of n-pentane over the catalyst was investigated as well. The results show that the skeletal isomerization and the crack of n-pentane proceed simultaneously on WC-supported S2O2-8/ZrO2 catalyst. The addition of tungsten carbide showed a significant enhancement in the activity and stability of the catalyst for n-pentane isomerization. The catalyst showed evidently a better activity than S2O2-8/ZrO2 supported by Pt and WO3. The results can be interpreted by the existence of the tungsten oxycarbide compound(WCxOy) with carbidic, oxide and acidic sites.     

固体强酸催化剂S_2O_8~(2-)/ZrO_2-Al_2O_3-M_2O_3(M=Cr,Ce,La)的制备

固体强酸具有酸强度高 ,不腐蚀设备 ,不污染环境 ,与产物分离方便等特点 ,是一种对环境友好的催化剂。业已发现固体强酸对许多重要的有机反应如烃类异构化、傅克酰基化、傅克烷基化、酯化、缩合、聚合、氧化等具有良好的催化活性 ,可替代传统的浓 H2 SO4 及 Al Cl3、HF等高污染催化剂。在前文 [1]基础上 ,本文通过添加 Cr2 O3、Ce2 O3和 La2 O3对催化剂 S2 O2 - 8/Zr O2 - Al2 O3改进后制备出 S2 O2 - 8/Zr O2 -Al2 O3- M2 O3( M=Cr,Ce,La)系列固体强酸催化剂 ,用对乙酸和正丁醇的酯化转化率评价了催化活性 ,用 XRD、BET、流…     

碳化钨负载S2O8^2-/ZrO2固体超强酸催化剂上的正戊烷反应研究

首次研究了碳化钨负载S2 O2 -8 ZrO2 (PSZ)固体超强酸催化剂 (WC PSZ)上正戊烷的反应情况及影响催化剂活性的各种因素 ,并用GC MS ,XRD ,BET等手段分析了正戊烷反应产物和催化剂的物理化学性质等 .结果表明 :WC PSZ对正戊烷具有异构化和裂解的双重催化作用 .PSZ在负载适量碳化钨后对正戊烷反应的活性和选择性显著提高 ,显示出优于Pt PSZ催化剂的效果 ,碳化钨的负载量为 2 0 %的效果最佳 .适当的焙烧、活化和反应温度等条件是取得良好反应效果的关键     

碳化钨负载S2O8^2-/ZrO2固体超强酸催化剂上的正戊烷反应研究

首次研究了碳化钨负载S2O8^2-/ZrO2(PSZ)固体超强酸催化剂(WC/PSZ)上正戊 烷的反应情况及影响催化剂活性的各种因素，并用GC-MS，XRD，BET等手段分析了 正戊烷反应产物和催化剂的物理化学性质等。结果表明：WC/PSZ对正戊烷具有异构 化和裂解的双重催化作用。PSZ在负载适量碳化钨后对正戊烷反应的活性和选择性 显著提高，显示出优于Pt／PSZ催化剂的效果，碳化钨的负载量为20％的效果最佳 。适当的焙烧、活化和反应温度等条件是取得良好反应效果的关键。     

在SO4^2-／ZrO2-MCM-41上苯与丙烯的烷基化

硅基介孔材料M41S因具有较大的孔径和比表面积而引起从事多相催化、吸附分离以及非金属材料等领域研究人员的极大关注，其中MCM-41是最具代表性的成员之一，但纯硅的MCM-41因无活性中心而不能用于催化领域，最近已有将SO4^2-／ZrO2超强酸及杂多酸负载到MCM-41上，使其成为     

碱金属助剂对MnOx／ZrO2催化合成

 研究了MnOx／ZrO2催化剂中添加的碱金属助剂对以合成气合成甲醇及异丁醇反应的影响，并采用BET，XRD和NH3－TPD等表征技术，考察了碱金属助剂的添加对催化剂结构和表面性质的影响．结果表明，碱金属助剂对MnOx／ZrO2催化剂的催化性能有明显影响．在实验条件下，添加1．0％K（K2CO3作为前驱物）的催化剂，其催化性能最好，醇的选择性高达74．8％，异丁醇选择性达16．3％．添加碱金属助剂也使MnOx／ZrO2催化剂的表面性质发生了很大变化，从而影响催化剂的催化性能．     

微乳液法制备Pt-S2O82-/ZrO2-Al2O3型固体超强酸催化剂及其异构化性能

采用微乳液法负载Pt制备了Pt-S2O82-/ZrO2-Al2O3(Pt-SZA-M)固体超强酸催化剂, 以正戊烷异构化反应为探针, 对比了微乳液法和浸渍法负载Pt制备的催化剂(Pt-SZA)的异构化性能, 并采用XRD, FTIR, BET, TG-DTA, TPR和TEM对催化剂进行了表征. 结果表明, 与Pt-SZA催化剂相比, Pt-SZA-M催化剂中Pt粒子的粒径更小(4.5 nm)且尺寸更均一; Pt-SZA-M催化剂的比表面积(109.6 m2/g)比Pt-SZA催化剂(95.0 m2/g)增加了15.4%. Pt-SZA-M催化剂的初始还原温度比Pt-SZA催化剂降低了10~20℃, 表明微乳液法负载Pt可以提高催化剂的氧化活性, 提高氢分子在催化剂上的吸附解离能力. 异构化活性实验结果表明, 与Pt-SZA催化剂相比, Pt-SZA-M催化剂的低温活性得到明显改善, 在反应压力为2.0 MPa、 氢烃摩尔比为4: 1、 质量空速为1.0 h-1的条件下, Pt-SZA-M催化剂在反应温度为230℃时活性达到60.8%, 在100 h内异戊烷的收率可稳定在58.0%左右, 选择性在95.0%以上.     

Catalytic Synthesis of Isopropyl Benzene over SO4^2-/ZrO2 -MCM-41

Introduction Owingtotheirlargeporediametersandlargesur faceareas,silicon basedmolecularsieves(M41S)have receivedmuchattention[1—5]inthefieldsofcatalytic reactions,adsorptiveseparations,andnonmetallicma terialsscience.MCM41isthemosttypicalmaterialof thisk…     

Al含量对Pt-S2O82-/ZrO2-Al2O3型固体超强酸催化剂异构化性能的影响

通过向S₂O₈^2-/ZrO₂催化剂中同时引入适量的Pt和Al₂O₃, 制备出了具有较高催化性能和高稳定性的Pt-S₂O₈^2-/ZrO₂-Al₂O₃型固体超强酸催化剂. 以正戊烷异构化反应为探针, 考察了Al含量对催化剂的异构化性能的影响, 并采用XRD, BET, FTIR, TPR, TG-DTA, NH₃-TPD和ICP手段对催化剂进行了表征. 结果表明, Al能够延迟ZrO₂的晶化温度, 抑制硫的分解; Al能够增加催化剂的比表面积, 增强硫氧键的结合, 提高催化剂的还原性能, 增加催化剂的酸强度和酸总量. 当Al₂O₃质量分数为2.5%时, Pt-S₂O₈^2-/ZrO₂-Al₂O₃固体超强酸催化剂的催化活性最高, 正戊烷异构化收率可达60.02%, 选择性在98.2％以上.     

SO2-4/ZrO2-Al2O3及载Pt催化剂上正丁烷异构化反应

研究了ＳＯ４＾２－／ＺrＯ２－Ａl２Ｏ３固体超强酸催化剂与制备条件的关系,探讨了催化剂表面结构及晶化程度,并在Ｎ２活化条件下用脉冲色谱法考察了催化剂催化正丁烷异构化反庆活性。结果表明,添加Ａ１可提高催化剂的催化剂的催化活性,降低反应温度,载铂对提高催化剂的活性和稳定性更为有效。