负载型燃烧催化剂La_(0.8)Ce_(0.2)CoO_3/Ce_(0.8)Zr_(0.2)O_2制备及性能研究

以复合氧化物La0.8Ce0.2CoO3为活性组分,Ce0.8Zr0.2O2固溶体为载体,采用柠檬酸络合法制备出负载型燃烧催化剂La0.8Ce0.2CoO3/Ce0.8Zr0.2O2。用XRD、BET和SEM对其进行表征,考察了焙烧温度、反应时间、反应温度及H2S存在对催化剂活性的影响。结果表明,载体表面形成了均一的钙钛矿相;该负载型催化剂对二甲苯完全氧化反应具有较高的催化活性,有良好的热稳定性、操作稳定性和强的抗H2S毒化能力。这可能是载体与负载组分之间密切的协同作用所导致。     

催化剂及其制备对催化湿式氧化反应的影响

催化湿式氧化法是一种有效的处理有毒、有害、高浓度有机废水的水处理技术,文章专门针对催化剂本身的制备对催化湿式氧化的影响,以及催化剂的失活、再生、重复利用等研究做出总结,以期对有关研究者提供一定的参考。     

石化废水深度处理用臭氧催化氧化体系的研究＊

文章就臭氧催化氧化体系在石化废水处理中的作用进行了深入研究,对催化剂载体、催化剂配伍体系以及臭氧的投加方式进行了优化筛选。根据实验,多元催化掺杂体系较一元催化体系氧化效果好,CODCr的去除率可由一元催化时的20%提高到多元催化时的33%;在臭氧的投加方式上,分段投加要优于单级投加,臭氧投加分配比例为6∶3∶1时,CODCr的去除率可由单一投加时的9%提高到分级投加时的19%。     

钙钛矿型催化剂La_（0.8）M_（0.2）CoO_3（M=Sr、Ce、Ba、Ca）催化燃烧VOCs的活性与抗硫性研究

用柠檬酸溶胶-凝胶法制备了La0.8M0.2CoO3（M=Sr、Ce、Ba、Ca）4种钙钛矿型复合氧化物催化剂.甲苯催化燃烧活性测试表明,4种催化剂均具有很好的催化活性,转化率达到90%时反应温度都在340℃以下,比LaCoO3下降20℃—70℃,催化性能依次为：La0.8Sr0.2CoO3〉La0.8Ce0.2CoO...     

柴油车尾气碳烟颗粒催化消除研究进展

本文针对柴油车尾气中碳烟颗粒污染环境的问题,综述了国内外关于碳烟颗粒催化消除及其作用机理的研究进展.指出了转换频率(TOF)更能从真正意义上表征催化剂的内在活性,从而有利于认识真实的反应机制和开发更高活性的催化剂.基于碳烟催化燃烧技术的特点和存在的问题,对今后相关的研究工作进行了展望.     

钒基催化剂同步去除燃煤烟气中甲苯与NOx研究

采用不同工艺制备V₂O₅-WO₃-MoO_x/TiO₂堇青石整体式催化剂,以甲苯和NO为探针分子,考察了Mo的负载量、涂覆方法、粘结剂的种类等制备工艺对整体式催化剂性能的影响,用XRD、SEM-EDS、FT-IR、BET等技术对催化剂进行了表征分析.结果表明,采用涂敷法,以添加量为1%的甲基纤维素为粘结剂所制备的V1W6Mo3/TiO₂堇青石蜂窝陶瓷整体式催化剂具有最优活性和稳定性（T₉₀为307℃,负载率为28.26%,脱落率为6.81%）,在燃煤烟气中具有优异的同步去除VOCs与NO性能,甲苯去除率可达99%,NO去除率为100%,N₂选择性为99%.XRD、SEM-EDS表明V、W、Mo活性组分分布均匀且高度分散.FT-IR证明添加甲基纤维素的整体式催化剂具有优异的抗硫性能.     

Efficient degradation of Rhodamine B by magnetically recoverable Fe3O4-modified ternary CoFeCu-layered double hydroxides via activating peroxymonosulfate

Environment-friendly nano-catalysts capable of activating peroxymonosulfate (PMS) have received increasing attention recently. Nevertheless, traditional nano-catalysts are generally well dispersed and difficult to be separated from reaction system, so it is particularly important to develop nano-catalysts with both good catalytic activity and excellent recycling efficiency. In this work, magnetically recoverable Fe₃O₄-modified ternary CoFeCu-layered double hydroxides (Fe₃O₄/CoFeCu-LDHs) was prepared by a simple co-precipitation method and initially applied to activate PMS for the degradation of Rhodamine B (RhB). X-ray diffraction (XRD), fourier transform infrared spectrometer (FT-IR), scanning electron microscope (SEM), transmission electron microscopy (TEM), Brunauer-Emmett-Teller method (BET), and vibrating sample magnetometer (VSM) were applied to characterize morphology, structure, specific surface area and magnetism. In addition, the effects of several key parameters were evaluated. The Fe₃O₄/CoFeCu-LDHs exhibited high catalytic activity, and RhB degradation efficiency could reach 100% within 20 min by adding 0.2 g/L of catalyst and 1 mmol/L of PMS into 50 mg/L of RhB solution under a wide pH condition (3.0-7.0). Notably, the Fe₃O₄/CoFeCu-LDHs showed good super-paramagnetism and excellent stability, which could be effectively and quickly recovered under magnetic condition, and the degradation efficiency after ten cycles could still maintain 98.95%. Both radicals quenching tests and electron spin resonance (ESR) identified both HO? and SO₄^?? were involved and SO₄^?? played a dominant role on the RhB degradation. Finally, the chemical states of the sample's surface elements were measured by X-ray photoelectron spectroscopy (XPS), and the possible activation mechanism in Fe₃O₄/CoFeCu-LDHs/PMS system was proposed according to comprehensive analysis.     

碳化泡沫负载Co3O4活化过硫酸盐降解罗丹明B

Co₃O₄具有优良的活化过硫酸盐的性能而受到人们的重视,但Co₃O₄粉体易团聚、使用过程中难以分离、易流失和重复利用率差等问题严重制约了其实际应用．通过水热法制备碳化三聚氰胺泡沫负载Co₃O₄非均相催化剂．采用X-射线衍射仪（XRD）和扫描电子显微镜（SEM）对催化剂的结构和表面形貌进行分析．研究不同因素对催化剂活化过硫酸氢钾（PMS）降解罗丹明B（RhB）的性能．其最优催化工艺参数：催化剂投加量为35 mg·L^-1、PMS质量浓度为50 mg·L^-1和pH为7、RhB初始质量浓度为10 mg·L^-1,30 min反应后对RhB降解率为98%．结果表明,增大碳化泡沫负载Co₃O₄非均相催化剂投加量和PMS质量浓度能明显提高对RhB的降解率;而增加RhB初始质量浓度和提高pH值会明显抑制RhB的降解率．催化反应过程符合准一级动力学方程．温度对RhB降...     

废FCC催化剂对水中铅离子的连续吸附及脱附

通过测定吸附等温线，考察了Ｐｂ２＋在废ＦＣＣ（流化催化裂化）催化剂上的吸附性能及规律，结果表明，Ｐｂ２＋在废ＦＣＣ催化剂上的吸附规律可用Ｌａｎｇｍｕｉｒ和Ｆｒｕｎｄｌｉｃｈ模式描述，吸附呈单分子层形式且容易进行。又通过填充床吸附试验，对Ｐｂ２＋的连续吸附及脱附情形作了考察。结果表明，在温度为１５℃、ｐＨ为５．１３、过柱速率为３．０ｍＬ／ｍｉｎ、径高比为２．２５．０条件下，吸附柱具备适宜的生产周期，连续吸附操作可行，柱效率可达７５．９％；在温度为１５℃、采用２ｍｏｌ／Ｌ稀盐酸作脱附剂，过柱速率为５．０ｍＬ／ｍｉｎ的条件下，吸附剂易于脱附再生，脱附效率可达７８．１％     

Semi-closed synthesis of nitrogen and oxygen Co-doped mesoporous carbon for selective aqueous oxidation

Heteroatom-doped meso/micro-porous carbon materials are conventionally produced by harsh carbonization under an inert atmosphere involving specific precursors, hard/soft templates, and heteroatom-containing agents. Herein, we report a facile synthesis of N and O co-doped meso/micro-porous carbon (NOMC) by template-free carbonization of a small-molecule precursor in a semi-closed system. The semi-closed carbonizaiton process yields hydrophilic NOMCs with large surface area in a high yield. The porous structure as well as the elemental composition of NOMCs can be modulated by changing the holding time at a particular temperature. NOMCs as metal-free heterogeneous catalysts can selectively oxidize benzyl alcohol and its derivatives into aldehydes/ketones with>85％conversion in aqueous solution, which is much higher than that of the control sample obtained in tube furnace (21％conversion), mainly due to their high N content, high percentage of pyridinic N, and large surface area. The presence of O-containing moieties also helps to improve the hydrophilicity and dispersion ability of catalysts and thus facilitates the mass transfer process during aqueous oxidation. The NOMC catalysts also dispayed excellent activity for a wide range of substrates with a selectivity of>99％.