Fe—Mo／KZSM—5上甲醇氧化为甲醛的研究

采用浸渍法制备了Ｆｅ／Ｍｏ／ＨＺＳＭ－５和Ｆｅ－Ｍｏ／ＫＺＳＭ－５分子筛催化剂,利用ＮＨ３－ＴＰＤ和Ｏ２－ＴＰＤ对催化剂的表面酸性和吸附Ｏ２物种进行了表征,考察了温度、Ｍｏ／Ｆｅ摩尔比,空气／甲醇摩尔比及ＷＨＳＶ对催化性能的影响。实验结果表明,在Ｆｅ－Ｍｏ／ＫＺＳＭ－５催化剂上,适宜的反应条件下,甲醇转化率接近１００％,甲醛选择性达到９０．６％,同时还进行了９６ｈ的催化剂的稳定性实验。     

合成气制低碳烯烃K—Fe—MnO／MgO催化剂的研究：Ⅰ.MnO助剂的作用

采用ＣＯ加氢反应、ＣＯ－ＴＰＤ、ＣＯ／Ｈ２－ＴＰＳＲ及Ｃ２Ｈ２／Ｈ２－ＴＰＳＲ等手段，研究合成气制低碳烯烃反应Ｋ－Ｆｅ－ＭｎＯ／ＭｇＯ催化剂中ＭｎＯ的助剂作用。结果表明ＭｎＯ能大幅度提高低碳烯烃的选择性，尤其是乙烯的选择性；ＭｎＯ能抑制催化剂表面的乙烯加氢，因而有利于提高低碳烯烃的选择性及烯／烷的比值。     

Fe—Silicalite—2催化剂表面CO2加氢反应性能的研究

研究了Ｆｅ／Ｓｉｌｉｃａｌｉｔｅ－２催化剂ＣＯ２加氢低碳烯烃反应性能，利用ＣＯ２－ＴＰＤ，ＣＯ２／Ｈ２－ＴＰＳＲ和ＣＯ／Ｈ２－ＴＰＳＲ表征手段，考察了铁含量及ＭｎＯ助剂对Ｆｅ／Ｓｉｌｉｃａｌｉｔｅ－２催化剂ＣＯ２吸附脱附及加氢反应性能的影响，表明随铁含量增加可提高催化剂对ＣＯ２的吸附能力，有利于提高ＣＯ２加氢反应的转化率。     

硅铁ZSM-48沸石的CO加氢催化性能

考察了硅铁ＺＳＭ－４８负载铁、钾催化剂在ＣＯ加氢制备低碳烯烃反应中的催化性能。结果表明,Ｆｅ（Ⅲ）离子同晶取代Ｓi（Ⅳ）后,不仅使沸石分子筛的表面能量分布更加趋 于均匀,而且明显促进了活性组分铁的还原和减弱了催化剂表面吸附氢的能力,从而大大提高了反应活性和选择性。硅铁ＺＳＭ－４８负载过量的铁、钾都不利于ＣＯ加氢合成低碳烯烃,其负载量的量侍值分别为８％和１．９％。另外,硅铁ＺＳＭ－４８的焙烧温度和焙烧     

合成气制低碳烯烃K－Fe－MnO／MgO催化剂的研究Ⅰ．MnO助剂的作用

采用ＣＯ加氢反应、ＣＯ－ＴＰＤ、ＣＯ／Ｈ＿２－ＴＰＳＲ及Ｃ＿２Ｈ＿４／Ｈ＿２－ＴＰＳＲ等手段，研究合成气制低碳烯烃反应Ｋ－Ｆｅ－ＭｎＯ／ＭｇＯ催化剂中ＭｎＯ的助剂作用。结果表明ＭｎＯ能大幅度提高低碳烯烃的选择性，尤其是乙烯的选择性；ＭｎＯ能抑制催化剂表面的乙烯加氢，因而有利于提高低碳烯烃的选择性及烯／烷的比值。     

Fe-Mo/KZSM-5上甲醇氧化为甲醛的研究

采用浸渍法制备了ＦｅＭｏ／ＨＺＳＭ５和ＦｅＭｏ／ＫＺＳＭ５分子筛催化剂,利用ＮＨ３ＴＰＤ和Ｏ２ＴＰＤ对催化剂的表面酸性和吸附Ｏ２物种进行了表征,考察了温度、Ｍｏ／Ｆｅ摩尔比、空气／甲醇摩尔比及ＷＨＳＶ对催化性能的影响．实验结果表明,在ＦｅＭｏ／ＫＺＳＭ５催化剂上,适宜的反应条件下,甲醇转化率接近１００％,甲醛选择性达到９０６％．同时还进行了９６ｈ的催化剂的稳定性实验     

Fe2O3/ZrO2催化剂上一氧化碳加氢反应制低碳烯烃Ⅱ.预处理条件对催化剂结构及性能的影响

用ＴＰＲ，Ｍｏｓｓｂａｕｅｒ谱法，ＸＰＳ，ＳＲＤ及反应评价等手段了Ｆｅ２Ｏ３／ＺｒＯ２催化剂的还原行为，铁物种状态和ＣＯ加氢反应性能，结果表明，预处理条件明显影响Ｆｅ２Ｏ３／ＺｒＯ２催化剂表面铁原子的数量、铁锆间的相互作用，催化剂的物相变化以及Ｃ氢反应的催经性能，以Ｆｅ２Ｏ２／ＺｒＯ２经氢氩混合氯程序升温至７５３Ｋ还原生成的Ｆｅ－Ｚｒ－Ｏ物种为前身，在合成气中进一步还原得到的铁锆催化剂，具有较好的     

THE CONVERSION OF SYNGAS ON Fe／MnOⅡ．The Role of K in Modified Fe／MnO Catalysts

ＴＨＥＣＯＮＶＥＲＳＩＯＮＯＦＳＹＮＧＡＳＯＮＦｅ／ＭｎＯⅡ．ＴｈｅＲｏｌｅｏｆＫｉｎＭｏｄｉｆｉｅｄＦｅ／ＭｎＯＣａｔａｌｙｓｔｓＧｕａｎＮａｉｊｉａ（ＤｅｐａｒｔｍｅｎｔｏｆＣｈｅｍｉｓｔｒｙ，ＮａｎｋａｉＵｎｉｖｅｒｓｉｔｙ，Ｔｉａｎｊｉｎ３０...     

Fe_2O_3／ZrO_2催化剂上一氧化碳加氢反应制低碳烯烃 Ⅱ．预处理条件对催化剂结构及性能的影响

用ＴＰＲ，Ｍｏｓｓｂａｕｅｒ谱法，ＸＰＳ，ＸＲＤ及反应评价等手段研究了Ｆｅ２Ｏ３／ＺｒＯ２催化剂的还原行为、铁物种状态和ＣＯ加氢反应性能．结果表明，预处理条件明显影响Ｆｅ２Ｏ３／ＺｒＯ２催化剂表面铁原子的数量、铁锆间的相互作用、催化剂的物相变化以及ＣＯ加氢反应的催化性能．以Ｆｅ２Ｏ３／ＺｒＯ２经氢氟混合气程序升温至７５３Ｋ还原生成的Ｆｅ－Ｚｒ－Ｏ物种为前身，在合成气中进一步还原得到的铁锆催化剂，具有较好的Ｆ－Ｔ反应合成低碳烯烃的选择性．     

Mn—ZSM—48的制备与表征

报道了新型杂原子分子筛Ｍｎ－ＺＳＭ－４８的合成与表征。红外光谱和紫外漫反射光谱测试表明Ｍｎ（Ⅱ）离子进入了分子筛骨架。Ｍｎ（Ⅱ）同晶取代Ｓｉ（Ⅳ）导致产物晶粒的形貌和热性质有所不同。反应混合物中１,６－己二胺的含量,水含量和Ｓｉ／Ｍｎ比对产物的晶化有很大影响。Ｍｎ－ＺＳＭ－４８作为ＣＯ加氢合成低碳烯烃的催化剂载体较Ｓｉ－ＺＳＭ－４８显示出很高的催化活性和明显的选择性。     

Effects of Coke Deposits on the Catalytic Performance of Large Zeolite H‐ZSM‐5 Crystals during Alcohol‐to‐Hydrocarbon Reactions as Investigated by a Combination of Optical Spectroscopy and Microscopy

The catalytic activity of large zeolite H‐ZSM‐5 crystals in methanol (MTO) and ethanol‐to‐olefins (ETO) conversions was investigated and, using operando UV/Vis measurements, the catalytic activity and deactivation was correlated with the formation of coke. These findings were related to in situ single crystal UV/Vis and confocal fluorescence micro‐spectroscopy, allowing the observation of the spatiotemporal formation of intermediates and coke species during the MTO and ETO conversions. It was observed that rapid deactivation at elevated temperatures was due to the fast formation of aromatics at the periphery of the H‐ZSM‐5 crystals, which are transformed into more poly‐aromatic coke species at the external surface, preventing the diffusion of reactants and products into and out of the H‐ZSM‐5 crystal. Furthermore, we were able to correlate the operando UV/Vis spectroscopy results observed during catalytic testing with the single crystal in situ results.     

ZSM—5芳构化反应活性和稳定性的研究

ＺＳＭ－５以其独特的基于微孔结构特征的形状选择性和强酸中心，而成为具有酸催化择形性能的新型分子筛催化剂．ＺＳＭ－５分子筛表面酸性中心不但是反应的活性中心，同时也是积炭中心，这使得这类催化剂不仅具有很高的催化反应活性，同时也具有较高的结焦活性．催化剂表...     

纳米ZSM-5用于石脑油催化裂化的最新进展(英文)

综述了纳米ZSM-5在石脑油催化裂解中的应用.比较了纳米ZSM-5和毫米级ZSM-5对产物选择性、反应转化率和催化剂寿命的影响.纳米ZSM-5的应用不仅延长了催化剂寿命,而且表现出更稳定的轻质烯烃选择性.讨论了反应条件,如温度和进料对纳米ZSM-5催化性能的影响,发现高温和线式烷烃作为进料时可提高轻质烯烃的选择性和反应转化率.     

Theoretical Insights on Methylbenzene Side‐Chain Growth in ZSM‐5 Zeolites for Methanol‐to‐Olefin Conversion

The key step in the conversion of methane to polyolefins is the catalytic conversion of methanol to light olefins. The most recent formulations of a reaction mechanism for this process are based on the idea of a complex hydrocarbon‐pool network, in which certain organic species in the zeolite pores are methylated and from which light olefins are eliminated. Two major mechanisms have been proposed to date—the paring mechanism and the side‐chain mechanism—recently joined by a third, the alkene mechanism. Recently we succeeded in simulating a full catalytic cycle for the first of these in ZSM‐5, with inclusion of the zeolite framework and contents. In this paper, we will investigate crucial reaction steps of the second proposal (the side‐chain route) using both small and large zeolite cluster models of ZSM‐5. The deprotonation step, which forms an exocyclic double bond, depends crucially on the number and positioning of the other methyl groups but also on steric effects that are typical for the zeolite lattice. Because of steric considerations, we find exocyclic bond formation in the ortho position to the geminal methyl group to be more favourable than exocyclic bond formation in the para position. The side‐chain growth proceeds relatively easily but the major bottleneck is identified as subsequent de‐alkylation to produce ethene. These results suggest that the current formulation of the side‐chain route in ZSM‐5 may actually be a deactivating route to coke precursors rather than an active ethene‐producing hydrocarbon‐pool route. Other routes may be operating in alternative zeotype materials like the silico‐aluminophosphate SAPO‐34.     

轻烃在改性ZSM－5催化剂上转化成芳烃与低碳烯烃的选择性控制

研究了Ｃ３－Ｃ９烷烃在不同的改性ＺＳＭ－５沸石上的反应规律．过渡金属离子改性的ＺＳＭ－５沸石显示了较高的芳烃选择性，芳烃的选择性还取决于改性金属离子的脱氧能力并可通过预硫化得到改进．钾、钡改性的沸石显示了较高的烯烃选择性，增加钾含量，烯烃选择性显著提高，但也明显抑制了催化剂的活性；提高Ｂａ含量，同样可提高烯烃选择性，但对活性影响不大．环己烯的模型反应结果表明，Ｋ，Ｂａ的作用在于抑制了双分子氢转移反应和提高了脱氢能力．红外表征结果表明，沸石表面的羟基，因不同金属改性而发生不同的变化．此外，气相氧对提高烯烃和芳烃的收率有明显作用     

A Comparison of NO Reduction Over Mn–Cu/ZSM5 and Mn–Cu/MWCNTs Catalysts Assisted by Plasma at Ambient Temperature

Manganese–copper bimetal oxide catalysts supported on ZSM5 and acid-treated multi-walled carbon nanotubes (MWCNTs) were produced by incipient wetness impregnation for selective catalytic reduction of NO with dielectric barrier discharge plasma. Plasma can activate molecules even at ambient temperature, generating active oxygen species such as O, O₃, and HO₂ radicals, which can oxidize NO to NO₂ effectively. The SCR activity of Mn–Cu/MWCNTs was studied and compared to that of the Mn–Cu/ZSM5. The obtained samples were characterized by XRD, SEM, TEM, ICP, H₂-TPR, Raman spectroscopy, and XPS. The results show that Mn–Cu/MWCNTs catalyst possesses NO removal activity superior to that of the Mn–Cu/ZSM5 catalyst. MWCNTs-based catalyst attains NO removal efficiency of 88% at 480 J/L, while the ZSM5-supported catalyst achieves NO removal efficiency of 82% at the same energy density. The oxygen content increased from 3.33 to 19.07% on the nanotube surface after introducing Mn and Cu, which almost remained unchanged on ZSM5. The oxygen-containing functionalities are important for NO_x adsorption and removal. Moreover, the characterization revealed that CuO is the main phase of copper oxide, but copper dispersion decreases on Mn–Cu/ZSM5 surface because of the formation of copper dimer species. The manganese is well-dispersed on the catalysts, MnO₂ and Mn₂O₃ contents of Mn–Cu/MWCNTs are larger than that of Mn–Cu/ZSM5, MnO₂ is the predominant phase of manganese oxide.     

Highly Selective Olefin Production from CO2 Hydrogenation on Iron Catalysts: A Subtle Synergy between Manganese and Sodium Additives

Mn and Na additives have been widely studied to improve the efficiency of CO₂ hydrogenation to valuable olefins on Fe catalysts, but their effects on the catalytic properties and mechanism are still under vigorous debate. This study shows that Fe-based catalysts with moderate Mn and Na contents are highly selective for CO₂ hydrogenation to olefins, together with low selectivities for both CO and CH₄ and much improved space-time olefin yields compared to state-of-the-art catalysts. Combined kinetic assessment and quasi in situ characterizations further unveil that the sole presence of Mn suppresses the activity of Fe catalysts because of the close contact between Fe and Mn, whereas the introduction of Na mediates the Fe–Mn interaction and provides strong basic sites. This subtle synergy between Na and Mn sheds light on the importance of the interplay of multiple additives that could bring an enabling strategy to improve catalytic activity and selectivity.     

以金属氧化物及钙钛矿结构化合物为活性组分的ZSM-5催化剂上NOx选择性还原研究

研究了在水蒸汽存在条件下,以ＮＨ３为还原剂,金属／ＺＳＭ－５催化剂和负载于ＺＳＭ－５上的钙钛矿结构催化剂上的ＮＯｘ选择性催化还原（ＳＣＲ）性能。实验结果表明,当反应气中通入水蒸汽时,各样品的催化活性均下降,同时伴随着Ｎ２选择性的增加。而Ｃｕ－ＺＳＭ－５样品却表现出独特的性能,在所有测定样品中具有最高的ＮＯｘ转化率（在４５０℃时达到６９％）,当有水蒸汽存在时,其活性没有下降,反而有所增加,４５０℃时     

分散法制备的CuCl/ZSM-5分子筛催化剂上C3H6选择性催化还原NO反应的研究

研究了由分散法制备的CuCl/ZSM-5分子筛催化剂上丙烯在过量氧存在下选择催化还原NO反应,发现该法能使活性组份高度分散于载体上,且所制备的高负载量CuCl/H-ZSM-5与离子交换法制备的Cu-ZSM-5相比在较低反应温度下具有更高的反应活性.     

Au/Mn2O3/Al2O3催化剂的制备及其deNOx活性

由于燃煤烟气、汽车尾气的过度排放 ,大气中ＮＯｘ(其中ＮＯ占 90 %以上 )浓度已呈上升趋势。ＮＯ在阳光作用下 ,易形成光化学烟雾 ,危害人体的呼吸系统。ＮＯ还是破坏大气臭氧层和形成酸雨的前驱气体之一 ,破坏生态环境。催化分解和催化还原法是消除ＮＯ(ｄｅＮＯｘ)的主要方法。但由于实际环境中ＮＯ往往与某一种或几种还原性气体 (如ＣＯ、低碳烃 )共存 ,所以催化还原法是人们公认的有应用前景的ｄｅＮＯｘ 方法[1 ] 。近十几年来 ,国内外研究较多的ｄｅＮＯｘ 催化剂是Ｃｕ ＺＳＭ 5 ,其催化活性除受原料气中氧含量的影响外 ,很大程度上…