Genesis of site isolation and phase cooperation in selective oxidation catalysis

Two of the important principles governing selective oxidation catalysis are site isolation and phase cooperation. They are discussed here in light of their inception, development, historic perspective and current acceptance in the field of selective oxidation and ammoxidation catalysis.     

Au/SiO_2催化剂上丙烯空气氧化制丙烯醛

采用等体积浸渍法制备了Au/S iO2催化剂,X射线粉末衍射、透射电子显微镜表征结果显示,其金粒子的平均大小可控制在10nm以内。考察了反应温度、空速、金负载量、催化剂焙烧温度、添加助剂等对Au/S iO2催化剂催化丙烯空气氧化制丙烯醛反应性能的影响。实验结果表明,该催化剂具有很高的丙烯醛选择性。在325℃、原料气空速4 000h-1、V(C3H6)∶V(O2)=1∶2、反应时间120m in的条件下,采用500℃焙烧的Au/S iO2催化剂,当丙烯的转化率为1.0%时,丙烯醛的选择性达70%以上。提高焙烧温度至800℃,丙烯醛选择性可达90%。加入Cu助剂可以提高丙烯的转化率,但使丙烯醛选择性下降。     

改进Skraup法制备8-羟基喹啉的研究

采用改进的Skraup法,以丙烯醛代替甘油,以邻氨基苯酚、邻硝基苯酚、丙烯醛为原料在盐酸、醋酸存在的条件下合成了8-羟基喹啉.通过正交实验探讨了丙烯醛滴加时间、醋酸用量、丙烯醛用量、邻硝基苯酚用量、反应时间对产率的影响.确定最佳反应条件为:邻氨基苯酚用量为21.8 g(0.20 mol)、邻硝基苯酚用量为14.6 g(0.11 mol)、丙烯醛用量为20.2 g(0.36 mol)、醋酸用量为22.0 g(0.37 mol)、盐酸200 mL、丙烯醛滴加时间为3 h、加热反应时间为1.0 h.此时,8-羟基喹啉的产率达72%.     

合成丙烯酸用催化剂的研究进展

对近期丙烯选择氧化和丙烷选择氧化制丙烯酸的催化剂研究进行了综述,前者主要是钼-铋系列催化剂和钼-钒系列催化剂,后者涉及到钒-磷-氧（VPO）催化剂、杂多酸（HPA）及其盐催化剂以及以钼为主要成分的复合金属氧化物（CMO）催化剂。     

油脂热解生成丙烯醛的途径及规律研究

考察了油脂降解产物——甘油和脂肪酸受热降解生成丙烯醛的情况及其生成丙烯醛的途径。结果表明:在175℃加热条件下,甘油每小时生成丙烯醛平均量为106.95μg/kg,棕榈酸为551.33μg/kg,硬脂酸为263.23μg/kg,油酸为34 795.96μg/kg,亚油酸为24 395.15μg/kg;油脂热解生成的丙烯醛主要来自于脂肪酸的分解而非甘油,且不饱和脂肪酸生成丙烯醛的量远远高于饱和脂肪酸的;甘油主要通过脱水生成丙烯醛,饱和脂肪酸主要由于碳链在高温下断裂生成丙烯醛,而不饱和脂肪酸生成丙烯醛则是通过氧化,继而发生夺氢反应生成烯丙自由基,进一步断裂得到丙烯醛。     

Propane partial oxidation to acrolein over combined catalysts

A novel approach for the partial oxidation of propane to acrolein, based on the use of layers of combined catalysts in a single reactor, provides good yields of acrolein with selectivity above 62%. The results depend strongly on the layer configuration, and reveal new mechanistic features for the process. This revised version was published online in August 2006 with corrections to the Cover Date.     

Low-Dose Acrolein,an Endogenous and Exogenous Toxic Molecule,Inhibits Glucose Transport via an Inhibition of Akt-Regulated GLUT4 Signaling in Skeletal Muscle Cells

Urinary acrolein adduct levels have been reported to be increased in both habitual smokers and type-2 diabetic patients. The impairment of glucose transport in skeletal muscles is a major factor responsible for glucose uptake reduction in type-2 diabetic patients. The effect of acrolein on glucose metabolism in skeletal muscle remains unclear. Here, we investigated whether acrolein affects muscular glucose metabolism in vitro and glucose tolerance in vivo. Exposure of mice to acrolein (2.5 and 5 mg/kg/day) for 4 weeks substantially increased fasting blood glucose and impaired glucose tolerance. The glucose transporter-4 (GLUT4) protein expression was significantly decreased in soleus muscles of acrolein-treated mice. The glucose uptake was significantly decreased in differentiated C2C12 myotubes treated with a non-cytotoxic dose of acrolein (1 μM) for 24 and 72 h. Acrolein (0.5–2 μM) also significantly decreased the GLUT4 expression in myotubes. Acrolein suppressed the phosphorylation of glucose metabolic signals IRS1, Akt, mTOR, p70S6K, and GSK3α/β. Over-expression of constitutive activation of Akt reversed the inhibitory effects of acrolein on GLUT4 protein expression and glucose uptake in myotubes. These results suggest that acrolein at doses relevant to human exposure dysregulates glucose metabolism in skeletal muscle cells and impairs glucose tolerance in mice.