Oxidative dehydrogenation of ethane to ethylene in the presence of HCl over CeO_2-based catalysts

报道了一种HCl存在时温和条件下的乙烷氧化脱氢制乙烯催化转化新途径.研究发现,在多种金属氧化物催化剂中,CEO2呈现最佳乙烯生成的催化性能.与纳米粒子相比,具有棒状和立方体状形貌的CEO2纳米晶具有较高的乙烷转化率和乙烯选择性.以MnOX修饰CEO2可进一步提高催化性能.在8 WT%MnOX-CEO2催化剂上,723 k反应2 H时乙烷转化率和乙烯选择性分别为94%和69%.该催化剂性能稳定,反应100 H乙烯收率可保持在65%–70%.HCl的存在对乙烯的选择性生成起着至关重要的作用,一部分乙烯来自于氯乙烷的脱HCl反应.This article reports a new catalytic route for the oxidative dehydrogenation of ethane to ethylene in the presence of HCl at moderate temperatures.CeO2 was found to be the most efficient catalyst for the production of ethylene from the variety of metal oxides examined in this work.CeO2 nanocrys‐tals with rod and cube morphologies showed higher ethane conversions and ethylene selectivities than CeO2 nanoparticles.The modification of CeO2 by MnOx further enhanced the catalytic perfor‐mance.Ethane conversion of 94% and ethylene selectivity of 69% were obtained after 2 h of reac‐tion at 723 K over an 8 wt% MnOx-CeO2 catalyst.This catalyst was stable and the ethylene yield could be sustained at 65%–70% over 100 h of reaction.The presence of HCl played a key role in the selective production of C2H4, and some of the C2H4 was probably formed from chloroethane by de‐hydrochlorination.supportedbytheNationalBasicResearchProgramofChina(973Program;2010CB732303); theNationalNaturalScienceFoundationofChina(21033006); theProgramforChangjiangScholarsandInnovativeResearchTeaminUniversity(IRT1036)~

Application of Ti/RuO2-IrO2-SnO2-Sb2O5 Anode in Rural Drinking Water Disinfection

采用热分解法制备了一种新型高效析氯阳极Ti/RuO2-IrO2-SnO2-Sb2O5,将其应用于农村饮用水消毒频繁停开、低电解液浓度的特殊工况下,并与Ti/RuO2-SnO2-Sb2O5、Ti/RuO2-TiO2、Ti/RuO2-TiO2-IrO2三种析氯阳极进行性能对比。通过SEM、EDS、XRD等方法表征测试阳极表面形貌、元素及组成,考察了氯化钠浓度、电流密度、停开频率对阳极析氯效果和寿命的影响。研究发现,Ti/RuO2-IrO2-SnO2-Sb2O5阳极活性强、稳定性高;阳极涂层各组分高度融合为固溶体,结构致密,稳定性强;在15 g·L-1 NaCl、400 A·m-2电流密度、20℃条件下,Ti/RuO2-IrO2-SnO2-Sb2O5阳极电解的电流效率达到91.55%;频繁停开、强化电解条件下寿命达到231 h,是Ti/RuO2-TiO2阳极的77倍,预估在400 A·m-2电流密度下能够使用20年。Sodium hypochlorite disinfection has many advantages, including reliable operation, low cost, easily available raw materials. It is, therefore, suitable for disinfection of drinking water in remote rural areas. The service life and chlorine evolution efficiency of the anode are the main factors restricting the performance of the sodium hypochlorite generator. The special conditions of frequent shutdown and low electrolyte concentration in the rural drinking water application also put forward high requirements on the performance of the anode. In this study, Ti/RuO2-IrO2-SnO2-Sb2O5,a new-type and efficient chlorine evolution anode, was prepared by thermal decomposition method and further applied to disinfection of drinking water in rural areas. Comparison was also made between this anode with Ti/RuO2-SnO2-Sb2O5, Ti/RuO2-TiO2 and Ti/RuO2-TiO2-IrO2 anodes. The surface morphology, elements and composition of the anodes were examined by SEM, EDS and XRD. The effects of sodium chloride concentration, current density and shutdown frequency on chlorine evolution efficiency and lifetime of the anodes were also investigated. It was found that the Ti/RuO2-IrO2-SnO2-Sb2O5 electrode exhibited strong activity and high stability, and its coating components were highly fused into a solid solution with dense structure and great stability. The current efficiency of Ti/RuO2-IrO2-SnO2-Sb2O5 anode reached 91.55% in 15 g·L-1 NaCl solution at 400 A·m-2 and 20℃. In the enhanced electrolysis lifetime experiment, the service lifetime of Ti/RuO2-IrO2-SnO2-Sb2O5 anode reached 231 h, which was 77 times longer than that of Ti/RuO2-TiO2 anode. It was estimated that the Ti/RuO2-IrO2-SnO2-Sb2O5 anode could be used for 20 years under the current density of 400 A·m-2. Therefore, compared with the traditional electrode materials, Ti/RuO2-IrO2-SnO2-Sb2O5 achieved higher chlorine evolution efficiency and stability. It could be used for a long time in the condition of frequent shutdown and low electrolyte concentration. Besides, it could greatly reduce the equipment operation cost, the raw material feeding frequency and the impurities introduction. Thus, the Ti/RuO2-IrO2-SnO2-Sb2O5 anode developed in this studymight be suitable for rural drinking water disinfection application.国家重点研发计划项目(2019YFC0408800)通讯作者:陈雪明E-mail:[email protected]:Xue-MingChenE-mail:[email protected]浙江大学环境与资源学院,浙江 杭州 310058College of Environmental & Resource Sciences of Zhejiang University, Hangzhou 310058, Zhejiang, Chin

Electrocatalytic Reduction of L-cystine at Pb/nanoTiO_2 Film Electrode

采用阳极氧化和恒电位沉积法制备Pb纳米粒子修饰的多孔Ti基TiO2(Pb/nanoTiO2)膜电极.通过对不同的电沉积电位和时间对比,找出了最佳电沉积条件.SEM分析显示该膜为均匀多孔结构,Pb纳米粒子均匀地分散在TiO2膜的表面.循环伏安和计时电流法研究了L-胱氨酸在Pb/nanoTiO2膜电极上的电催化还原活性,结果表明该电极对L-胱氨酸的还原具有高催化活性和稳定性.The nanoporous Ti-based TiO2 films electrodes modified with Pb particles(Pb/nanoTiO2) were prepared by using anodization and potentiostatic electro-deposition.The optimum deposition conditions were determined by comparing with various deposition potentials and time.The SEM analyses indicated that the TiO2 films were homogeneous nanoporous structure,and the Pb particles well dispersed on the TiO2 films.The L-cystine electrocatalytic activity reduction on the Pb/nanoTiO2 film electrodes was investigated by cyclic voltammetry and Chronoamperometric curves.The results showed that this type of the electrode posseses high acticity and stability.作者联系地址：安徽师范大学安徽省功能性分子固体、分子基材料重点实验室化学与材料科学学院;安徽阜阳职业技术学院生化工程学院;Author's Address: 1.Anhui Key Laboratory of Functional Molecular Solids & Molecular Based Materials,College of Chemistry and Materials Science,Anhui Normal University,Wuhu 241000,Anhui,China;2.Department of chemistry,Vocational and Technical College of Fuyang,Fuyang 236000,Anhui,Chin

血管紧张素- (1- 7)预处理减轻大鼠离体心脏缺血再灌注损伤

【目的】 探讨较大剂量血管紧张素- (1- 7) 预处理对大鼠心肌缺血再灌注损伤的影响及其信号机制。【方法】48 只 SD 大鼠随机分为 4 组, 每组 12 只: 缺血再灌注对照组、血管紧张素- (1- 7)预处理组、血管紧张素- (1- 7)预处理加磷脂酰肌醇- 3 激酶( PI3K) 抑制剂 Wortmannin 处理组、Wortmannin 处理对照组, 观察较大剂量血管紧张素- (1- 7)预处理对大鼠离体缺血再灌注心脏左心室收缩压、冠状动脉流量、肌酸磷酸激酶和乳酸脱氢酶释放、心肌梗死范围以及心肌蛋白激酶 B( Akt) 、糖原合成酶激酶- 3β( GSK- 3β) 磷酸化的影响。【结果】与缺血再灌注对照组相比, 血管紧张素- (1- 7)预处理组心脏左心室收缩压、冠状动脉流量显著提高, 冠状动脉循环流出液中肌酸磷酸激酶、乳酸脱氢酶含量降低, 心肌梗死范围减小, 心肌磷酸化 Akt( Ser473) 、磷酸化 GSK-3β( Ser9) 水平增高, PI3K 抑制剂Wortmannin 能够抑制血管紧张素- (1- 7)预处理所致的Akt、GSK- 3β磷酸化, 但只能部分消除血管紧张素- (1- 7)预处理的心脏保护效应。【结论】较大剂量血管紧张素- (1- 7)预处理能够减轻大鼠离体心脏缺血再灌注损伤, PI3K/Akt/GSK- 3β信号通路参与介导血管紧张素- (1- 7) 预处理的心脏保护作用

氧化铁纳米棒的制备及在NOx消除中的应用

Synthesis of Iron Oxide Nanorods and Application in NOx Abatemen