Experimental and theoretical studies on NO selective catalytic oxidation over α-MnO2

Based on the experimental and theoretical methods, the NO selective catalytic oxidation process was proposed. The experimental results indicated that lattice oxygen was the active site for NO oxide over the $\mathrm{\alpha }$-MnO₂(110) surface. In the theoretical study, DFT (density functional theory) and periodic slab modeling were performed on an $\mathrm{\alpha }$-MnO₂(110) surface, and two possible NO oxidation mechanisms over the surface were proposed. The non-defect $\mathrm{\alpha }$-MnO₂(110) surface showed the highest stability, and the surface O_s (the second layer oxygen atoms) position was the most active and stable site. O₂ molecule enhanced the joint adsorption process of two NO molecules. The reaction process, including O₂ dissociation and O=N-O-O-N=O formation, was calculated to carry out the NO catalytic oxidation mechanism over $\mathrm{\alpha }$-MnO₂(110). The results showed that NO oxidation over the $\mathrm{\alpha }$-MnO₂(110) surface exhibited the greatest possibility following the route of O=N-O-O-N=O formation. Meanwhile, the formation of O=N-O-O-N=O was the rate-determining step.     

催化技术在污染物治理应用的研究进展

对近年来催化技术在污染物治理应用的研究进展进行了综述,指出了现在研究中存在的主要问题,并对其前景进行了展望。     

Catalytic dechlorination of chlorobenzene in water by Pd/Fe bimetallic system

IntroductionChlorinatedorganiccompoundshavebeenusedonalargescaleinthechemical,petrochemical,andelectronicindustries.Inrecentyears ,worldwideattentionhasbeengiventotheenvironmentalandhealthimpactofthemasaclassofcontaminants .Severalareknowntocauseozonedepletion ,whileothersproduceadverseeffectsonthehumancentralnervoussystemandhavebeenlinkedtodiseasessuchascancer.Almostallofthechlorinatedaromaticcompoundsaretoxicandthermallystable .Oncereleasedintoenvironment,theywillaccumulateinthesurroundings…     

Catalysts for decomposing ozone tail gas

The preparation of immobilizing-catalysts for decomposing ozone by using dipping method was studied. XRD, XPS and TEM were used to characterize the catalysts. The three kinds of catalysts were selected preferentially, and their catalytic activities were investigated. The results showed that the catalyst with activated carbon dipping acetate( active components are Mn:Cu = 3:2, active component proportion in catalyst is 15%, calcination temperature is 200℃ ) has the best catalytic activity for ozone decomposing. One gram of catalyst can decompose 17.6g ozone at initial ozone concentration of 2.5g/m^3 and the residence time in reactor of 0.1s. The experimental results also indicated that humidity of reaction system had negative effect on catalytic activity.     

催化裂化废水连续萃取脱酚研究

选用焦化粗柴油为萃取剂，在转盘萃取搭连续试验装置中，对催化裂化含酚废水进行脱酚预处理。结果表明，用焦化粗柴油做萃取剂，进水ｐＨ值为８０～９０不加调节；油水比（体积比）１７∶１～２１∶１；转盘转数１１００ｒ／ｍｉｎ，酚萃取脱除率达到８５％以上。萃取后的粗柴油依据现有工艺而进行加氢精制，不需进行再生等后处理。整个萃取工艺简单易行，能满足预处理的要求     

一种富稀土型三效催化剂的性能考察

对一种富烯土型三效催化剂的性能进行了考察，结果表明：该催化剂具有较好的三效活性和较好的启燃温度特性，具有较宛的空速适应范围，在空速为84000h^-1时，CO,NOx的转化率仍在90％以上，HC转化率仍在70％以上，该催化剂具有较好的耐老化性能，经实验室快速老化实验，即相当于实车行驶8万km,CO劣化系数，1.09,HC劣化系1．05，NOx劣化系数1．06，该催化剂经桑塔纳轿车整车28工况测试，其交化效果与该车配置的美国Engelherd公司的催化剂相当。     

Cu／A1-Ce-PILC在丙烯选择性催化还原NO反应中的失活研究

采用聚合羟基复合阳离子合成交联黏土A1-Ce-PILC，经SO4^2-改性后，以浸渍法制备了铜基交联黏土催化剂Cu／A1-Ce-PILC，并将其应用于C3H6选择性催化还原NO的反应，350℃时NO转化率达到最大值56％，700℃时下降至22％．为探究催化剂高温失活的原因，采用XPS、TPR、TGA、Py-IR和DSC对反应前后催化剂的物化性能进行了表征．结果表明，经过H2预处理活化后活性组分Cu物种以Cu^＋形式存在，而高温反应后Cu物种除以Cu^＋和Cu^2＋ 2种形式存在外，还出现了少量CuO物种；高温反应过程中A1-Ce-PILC上结构羟基和SO4^2-流失导致催化剂表面酸性减弱；此外，还存在表面积炭覆盖了部分活性中心并堵塞了催化剂孔道的现象．这三者的共同影响促进了C3H6深度氧化，抑制了NO还原，从而导致催化剂的失活．     

大气环境的光触媒净化技术

介绍了光触媒对大气环境净化的机理，着重讨论了TiO2光触媒的活性、固定以及对大气污染杨的处理过程、问题等，并对光触媒技术的未来作了展望，以期推动我国在光触媒技术方面的研究。     

SCR反应塔入口段烟气速度场的数值模拟

使用商业计算软件CFX5．7．1，采用标准k-ε湍流模型，模拟了SCR脱硝反应塔入口段烟气速度场，并分析比较了导流板对烟气速度场的影响及均匀SCR反应塔进口处烟气速度场的作用。     

多相催化湿式氧化法处理高浓度难降解有机废水的研究

在高压反应釜内，采用自制颗粒贵金属催化剂催化湿式氧化法处理高浓度饲料抗氧化剂合成废水，探讨了温度、压力、进水pH等反应条件对废水处理效果的影响。在温度为220℃、总压为8MPa条件下，COD，TOC，TN和色度的去除率分别达到77．0％，66．1％，70．2％，91％；处理后的废水pH很低，催化剂显示出较好的耐酸性；随进水pH的增加，COD的去除率逐渐降低，出水pH增加。