高活性非食用油脂和脂肪酸甲酯加氢负载型铜镍二元催化剂的研究

采用并流沉淀法制备了Cu-Ni/SiO2二元催化剂,研究了影响催化剂活性的主要因素:Cu/Ni比,SiO2加入量,焙烧温度和焙烧时间,得到最佳制备条件:Cu/Ni=1/2.5～1/2,(Cu Ni)/SiO2=13/7～3/1,焙烧温度350℃,焙烧时间3h。在(Cu Ni)∶SiO2=3∶1、Cu∶Ni=1∶2.5时,不经陈化,可以制得高活性低金属残存量的Cu-Ni/SiO2二元催化剂。催化剂用量为原料脂肪酸甲酯质量的0.5%,氢压1MPa左右,反应30min,脂肪酸甲酯碘值可从100以上降到1左右。加氢产物为白色固体,肉眼观察不到金属离子的残存。原料和氢化脂肪酸甲酯的红外光谱图表明,该催化剂没有使碳碳双键生成反式异构体,具有很好的选择性和稳定性。     

Cu-Ni合金结构的分子动力学模拟

采用EAM作用势对Cu-Ni合金的结构特性进行了MD模拟研究.通过FZ结构因子可发现,Cu含量的变化对结构因子的波动影响很小,键取向序参数和键对也表现出相似的变化规律,这表明液态Cu-Ni合金对成份变化不敏感,体系中的化学序较弱.将Cu70Ni30合金熔体的FZ结构因子与Waseda的实验结果进行对比,发现二者吻合得较好,表明EAM势可以很好地描绘Cu-Ni合金的结构特性.在快速冷却过程中,除了Cu20Ni80合金外,其他合金成份的双体分布函数的第二峰都发生了劈裂,标志着体系最终形成了非晶结构,而Cu20Ni80合金的双体分布函数却表现出晶体峰的特征.通过对键取向序参数、键型指数以及铜镍原子的有效扩散系数的分析表明,在快速冷却过程中,Cu20Ni80合金最终形成了hcp晶体结构.     

Graphene nanosheet as support of catalytically active metal particles in DMC synthesis

Novel graphene nanosheet(GNS) supported Cu-Ni bimetal catalysts were firstly synthesized and used for the direct synthesis of dimethyl carbonate(DMC).The experimental results demonstrated that GNS was an effective and convenient support for the fabrication of Cu-Ni/GNS bimetal catalyst.     

K2O对合成DMC用Cu-Ni/V2O5-SiO2催化剂性能的影响

V2O5 SiO2(VSiO) supported Cu Ni K2O catalysts for the synthesis of dimethyl carbonate were prepared using isovolumic impregnation. Based on TPR,TPD, IR and micro reactor techniques, the effect of K2O on the adsorption and reaction of CO2 and CH3OH on the catalyst were characterized. The results show that addition of K2O exerts obvious influence on the charge distribution of the active sites on Cu Ni/VSiO catalyst,increases the intensities of CO2 horizontal adsorption state, while that of the dissociation state of methanol descends. When the ratio of K is above 15 ％, K2CO3 is formed on the catalyst. Moreover,the main reaction products of CO2 and CH3OH on Cu Ni K2O/VSiO catalyst are still DMC, H2O, CO and CH2O,and with the addition of K2O, the conversion of reactants rise, but the selectivity of by-products decreases.     

Cu-Ni/La2O3热解C2H2制备碳纳米管的研究

Nano-sized and well-dispersed Cu-Ni/La₂O₃ can be obtained by reduction of LaCu_0.2Ni_0.8O₃ with the structure of perovskite. Using Cu-Ni/La₂O₃ as catalyst and C₂H₂ as carbon source, carbon nanotubes with a high yield and narrow diameter distribution can be obtained in the reaction temperature range of 650～700℃. Outer diameter of carbon nanotubes rangs from 9nm to 14nm. TG, Raman and XPS analysis indicate that carbon nanotubes prepared by Cu-Ni/La₂O₃ are relatively higher in graphitic degree.     

Cu-Ni合金在NaCl溶液中的孔蚀特性

采用慢速电位扫描法和电位台阶计时电流法分别研究铸态铜镍合金以及由机械合金化方法制备的纳米晶铜镍合金于不同浓度NaCl溶液中的孔蚀特性.讨论含Ni量,Cl-浓度等因素对合金孔蚀敏感性的影响,探讨了不同结构合金的孔蚀发展.