凝胶成型法制备加氢催化剂载体的研究与工业化生产

采用凝胶成型法制备加氢催化剂载体，并进行了工业放大试验。通过BET、NH3-TPD、H2-TPR等表征手段及实际的加氢反应性能评价对凝胶成型法制备的载体及加氢催化剂与常规方法进行对比分析，结果表明，采用凝胶成型法所制得的载体及催化剂均具有较高的孔体积和比表面积、较低的堆密度，其机械强度可满足工业要求，总酸量及中强酸酸量得到提升，催化剂活性组分与载体强结合力得到削弱，金属利用率提高，应用性能明显优于传统方法制备的加氢催化剂载体。通过该方法完成了加氢催化剂载体的工业生产，所生产的载体应用于天津院THDS-3加氢精制催化剂取得了良好的工业应用效果。     

Cd-ZSM-5沸石催化剂的制备、表征和芳构化催化性能

采用离子交换、浸渍和混合三种方法制备镉改性ZSM-5沸石催化剂,考察了改性方法和镉含量对催化剂的表面酸性和Cd状态以及芳构化性能的影响。结果表明,加入镉降低了B酸性,Cd~(2+)与沸石结合形成了L_(1612)酸中心,其生成量取决于改性方法和Cd含量,并与芳构化活性提高有直接关系。     

Sulfated zirconia catalysts: Are Brønsted acid sites the source of the activity?

The thermal decomposition products of pyridinium sulfate differ from those of pyridinium sulfate supported on zirconia which in turn differs from that of pyridine adsorbed on a sulfated zirconia. Unsupported pyridinium sulfate decomposes to produce pyridine and sulfuric acid, and these subsequently react to produce oxides of carbon and sulfur. Zirconia that is sulfated and then exposed to pyridine does not release detectable amount of pyridine during heating in an inert gas; rather the pyridine undergoes oxidation reduction reactions simultaneously to release CO₂ and sulfur compounds. Pyridinium sulfate supported on zirconia decomposes upon heating to release pyridine and sulfuric acid, which reacts with the zirconia. The desorption of pyridine in one case and only CO₂/SO_x in the other case suggests that sulfated zirconia does not contain Brønsted acidity that can form pyridinium sulfate.     

聚合物载体－稀土金属络合物的研究 ⅩⅢ．聚［苯乙烯－甲基丙烯酸β（甲基亚硫酰基）乙酯］的结构与其稀土金属络合物催化丁二烯聚合的活性

从测得的竞聚率计算了单体链节在聚［苯乙烯－甲基丙烯酸β（甲基亚硫酰基）乙酯］（ＰＳＭ）中的序列分布。苯乙烯（Ｓ）或甲基丙烯酸β（甲基亚硫酰基）乙酯（Ｍ）的长序列的概率随着ＰＳＭ中相应单体含量的增加而增加。对于Ｓ和Ｍ摩尔分数大致相等的ＰＳＭ，单体链节的长序列分布函数值相接近。用与此结构相近的ＰＳＭ合成的稀土金属络合物，其催化活性不佳。在Ｍ短序列分布和Ｓ长序列分布较高的情况下，络合物的催化活性最好。所得聚丁二烯的微观结构与ＰＳＭ中单体单元的分布无关。     

Nitric oxide reduction and carbon monoxide oxidation over carbon-supported copper-chromium catalysts

Carbon supported copper-chromium catalysts are shown to be very active for both the reduction of nitric oxide with carbon monoxide and the oxidation of carbon monoxide with oxygen. Mixed copper-chromium oxide active phases have good activity in the simultaneous removal of nitric oxide and carbon monoxide from exhaust gases. The influence of several catalyst variables has been investigated. The activity per volume of catalyst increases with increasing loading, while the intrinsic activity shows a maximum around C/M=100−50. An optimum catalyst for nitric oxide reduction and carbon monoxide oxidation has a copper/chromium ratio of 2/1. The apparent activation energy for the carbon monoxide oxidation over carbon supported copper-chromium catalysts is 77 kJ/mol, suggesting that the Cu---O bond rupture is the rate-limiting process. The reduction of nitric oxide takes place at higher temperatures. Since all catalysts have a low selectivity for molecular nitrogen formation at lower temperatures, the dissociation of nitric oxide is probably rate determining, resulting in a slightly reduced catalyst system. In an excess of carbon monoxide the reaction is first-order in nitric oxide and zero-order in carbon monoxide. Moisture inhibits the reaction by reversible competitive adsorption, whereas carbon dioxide does not. Oxygen completely inhibits the reduction of nitric oxide due to the more rapid reoxidation of the catalytic sites compared to nitric oxide. Therefore, the reduction of nitric oxide takes place only when all oxygen has been converted and, hence, is shifted to higher temperatures. As a possible consequence, the production of nitrous oxide is reduced. Nitric oxide and molecular oxygen react preferentially with carbon monoxide, so, in an excess of oxidizing component, gasification of the carbon support occurs at higher temperatures after carbon monoxide has been completely consumed.     

中变催化剂失活典型事例剖析

通过2起中变催化剂失活的事件，从理论上剖析其根源，并探讨防范的对策。     

碱金属离子对PtSn/Al2O3催化剂丙烷脱氢活性的影响

用吡啶吸附－红外光谱和热重法研究了Li^ 、Na^ 、K^ 碱金属离子对负载型PtSn/Al2O3催化剂在丙烷脱氢中活性的影响。结果表明，碱金属离子对催化剂表面酸性有调变作用，提高了PtSn/Al2O3催化剂脱氢选择性，引入适量的Li^ 和Na^ 可减少催化剂的积碳量，改善催化剂的稳定性，提高丙烷转化率和丙烯收率；而引入K^ 可减少催化剂的积碳量，但丙烷转化率和丙烯收率大幅下降。     

80kt/a硫磺回收装置国产化设计

介绍了无在线炉硫回收工艺的基本原理、技术特点和催化剂使用情况。已投用的工业装置运行结果证明 ,用该工艺设计的硫磺回收装置 ,硫回收率和尾气净化度高 ,投资少 ,能耗低 ,流程简单 ,操作控制方便 ,社会效益和经济效益显著 ,适用于同类装置的新建和改扩建项目 ,市场前景广阔。     

NGO-Ⅲ催化剂的异构化性能评价

直馏汽油非临氢高效异构化使用最新一代NGO－Ⅲ型催化剂，生产的产品汽油辛烷值、产品收率及催化剂稳定性等全面超过现用的工业催化剂，达到目前国内同类产品的领先水平。     

Revised Model of Strain in Ceria–Zirconia-Encapsulated Precious-Metal Particles

A previously proposed model of strain in ceria–zirconia-encapsulated precious-metal particles is revised to reflect several new observations: encapsulation of unstrained Pt particles, quantitative relation between partial reduction and the change in ceria–zirconia cell parameters, temperature/time dependence of strain relaxation/imposition in encapsulated Pd and Rh particles, and strained PdO. According to the revised model, the main cause of strain is partial oxidation of the precious metal (rather than the change in oxygen content of ceria–zirconia, as originally suggested).