柠檬酸改性对掺Ba纳米MgO及其担载的Ru氨合成催化剂性能的影响  

Effects of Citric Acid Modification on the Performance of Nano-Ba-MgO Support and Its Ru-Based Catalysts for Ammonia Synthesis

作　　者：霍超[1] 夏庆华[1] 潘美华[1] 杨霞珍[1] 骆燕[1] 刘化章[1] 

机构地区：[1]浙江工业大学化学工程与材料学院,浙江杭州310032

出　　处：《催化学报》2011年第2期315-320,共6页

基　　金：国家自然科学基金(20203016);浙江省自然科学基金(Y406294)

摘　　要：采用超声-静电吸附法制备了一系列经柠檬酸改性的掺Ba纳米MgO及其负载的氨合成Ru催化剂.并采用场发射扫描电镜、X射线粉末衍射、N2物理吸附-脱附、电感耦合等离子体发射光谱及红外光谱等手段对样品进行了表征.结果表明,适量添加柠檬酸可有效调控Ba的掺杂量,从而使Ba-MgO结构与化学性质发生变化,其表面性能得到极大改善,最终导致相应Ru/Ba-MgO催化剂氨合成的低温活性显著提高.在10MPa,400°C,10000h-1的条件下,柠檬酸浓度为2.0mmol/L时制得的Ru/Ba-MgO催化剂出口氨生成速率达63.2mmol/(g·h),较未经柠檬酸改性的Ru/Ba-MgO催化剂活性提高了21%.A series of citric acid-modified Ba-MgO supports（Ba-MgO（CA）） were prepared by ultrasound electrostatic adsorption（UEA） ,and the corresponding Ru catalysts for ammonia synthesis were then prepared by the impregnation method. Their physical and chemical properties were characterized by scanning electronic microscopy,X-ray diffraction,nitrogen physical adsorption,inductively coupled plasma-atomic emission spectrometry,and infrared spectroscopy. The results showed that the introduction of citric acid during the preparation of the support changed not only the chemical and textural properties of the nano-Ba-MgO support but also the doping amount of Ba in the Ba-MgO（CA） support. When the concentration of citric acid was 2.0 mmol/L,the Ru/Ba-MgO（CA） catalyst exhibited the highest catalytic activity for ammonia synthesis with a reaction rate of 63.20 mmol/（g·h） at 400 oC,10 MPa,and 10 000 h-1,which is 21% higher than that of unmodified Ru/Ba-MgO.

关 键 词：柠檬酸 改性 掺钡 纳米氧化镁 钌 氨合成 超声制备 

分 类 号：TQ113.21[化学工程—无机化工] O643.36[理学—物理化学]