摘要
采用水热法制备了一系列含铜类水滑石催化剂并进行焙烧改性,得到CuxMgyAlz-CHT-T系列催化剂,再采用碱金属调变催化剂碱性,得到M/CuxMgyAlz-CHT-T催化剂;采用X射线衍射、傅里叶变换红外光谱、扫描电子显微镜和N2吸附-脱附等方法对其进行表征;将该催化剂应用于催化甘油氧化反应中,考察了制备条件和反应条件对其催化性能的影响。结果表明,Cu和Mg的配比明显影响CuxMgyAlz-CHT-T的晶型结构和催化性能,其中Cu0.3Mg2.7Al1.0-CHT-450催化剂的催化甘油氧化反应的性能最好。甘油催化氧化反应的最佳条件为反应温度60℃、n(NaOH)/n(Glycerol)=8、氧气体积流速80mL/min、反应10h。在此条件下,甘油转化率为57.4%,甘油酸选择性可达73.7%。与相同反应条件下的未负载碱金属的Cu0.3Mg2.7Al1.0-CHT-450相比,采用5%Li/Cu0.3Mg2.7Al1.0-CHT-450催化剂所得甘油转化率可提高3.2百分点;但碱金属负载量过大时,金属离子堵塞孔道,可使催化性能降低。
A series of Cu-containing hydrotalcite catalysts (CuxMgyAlz-CHT-T) were synthesized by hydrothermal method and calcination modification under different temperatures(T). In addition, alkali metal supported M/CuxMgyAlz-CHT-T catalysts were prepared in order to increase catalytic activity. The prepared CuxMgsAlx-CHT-T and M/CuxMgyAlx-CHT-T were characterized by means of X-ray diffraction (XRD), Fourier transfer infrared spectroscopy (FT-IR), scanning electron microscopy(SEM) and N2 adsorption-desorption isotherms, and used in selective catalytic oxidation o{ glycerol. The effects of catalyst preparation and oxidation reaction conditions on glycerol conversion and product selectivity were investigated. The results showed that the molar ratio of Cu to Mg obviously affected the crystal structure and catalytic performance of CuxMgsAlz-CHT-T.Among the prepared CuxMgyA1x-CHT-T catalysts the Cu0.3 Mg2.7 Al1.0-CHT-450 possessed the highest catalytic performance for glycerol oxidation. The optimal reaction conditions with Cu0.3 Mg2.7Al1.0-CHT-450 as catalyst were the reaction temperature of 60℃, n(NaOH)/n(Glycerol)=8, oxygen volume flow rate of 80 mL/min, reaction time of 10 h, under which glycerol conversion rate was 57.4%, glycelic acid selectivity reached 73.7%. The conversion rate of glycerol increased by 3.2 percent when 5% Li/Cu0.3 Mg2.7 Al1.0-CHT-450 was used as catalyst, compared with Cu0. 3Mg2.7Al1.0-CHT-450 under the same reaction conditions. However, when the mass fraction of alkali metal supported on catalyst was excessive, the catalytic performance of the catalyst decreased, because the pores in catalyst were blocked.
出处
《石油学报(石油加工)》
EI
CAS
CSCD
北大核心
2013年第3期390-397,共8页
Acta Petrolei Sinica(Petroleum Processing Section)
基金
国家自然科学基金项目(21003073)
江苏省青蓝工程基金
南京工程学院校级科研基金项目(QKJB2010020,CKJ2010012)
江苏省高等学校大学生实践创新训练计划项目(166201110026)资助
关键词
类水滑石
选择性氧化
甘油
甘油酸
hydrotalcite
selective oxidation
glycerol
glyceric acid