丙烯醛氧化制丙烯酸的改性杂多酸催化剂研制

由丙烯两步氧化法生产丙烯酸的工艺中 ,主要问题在于找到选择性及转化率较好的 ,污染较小的催化剂。本文论述了 P Mo系杂多酸催化剂的性质对催化活性的影响     

双环戊二烯、丙烯醛法生产吡虫啉原药

简要介绍吡虫啉原药的用途和标准,以及采用双环戊二烯和丙烯醛法生产吡虫啉原药的生产工艺和原料要求。详细论述了吡虫啉原药生产的工艺流程,并对工业生产中主要工艺控制点和产品质量进行了讨论。最后提出了生产吡虫啉原药的三废治理方法。     

丙烷部分氧化制取丙烯醛Ⅰ.多组份氧化物催化剂的研究

对丙烷氧化制取丙烯醛的多组份氧化物催化剂进行了制备研究和ＴＰＲ、ＸＲＤ表征。结果表明Ｂｉ－Ｖ－Ｍｏ－Ｏ与Ｂｉ－Ｖ－Ｗ－Ｏ催化剂对丙烷氧化制取丙烯醛具有较高的活性与选择性，Ａｇ＋是优良助剂。添加Ａｇ＋调变的Ａｇ－Ｂｉ－Ｖ－Ｍｏ－Ｏ催化剂在４９０℃、０．００４ＭＰａ、３０００ｍｌ／（ｇｃａｔｈ）条件下，丙烷转化率为４６．９％，丙烯醛选择性为５２．８％。ＴＰＲ和ＸＲＤ研究表明，有优良催化性能的Ｂｉ－Ｖ－Ｍｏ－Ｏ和Ａｇ－Ｂｉ－Ｖ－Ｍｏ－Ｏ催化剂体系中具有白钨矿（ｓｃｈｅｅｌｉｔｅ）型的结构     

H_3PW_(12)O_(40)/SiO_2催化甘油制备丙烯醛的研究

采用等体积浸渍法合成了负载型H3PW12O40/SiO2催化剂,在常压连续流动的固定床反应器中,考察了其对甘油脱水制备丙烯醛的催化性能。结果表明,在反应温度为300℃,H3PW12O40杂多酸负载质量百分含量为30%时,催化剂具有较高的催化活性和生成丙烯醛的选择性,甘油的转化率达到98.2%,丙烯醛的摩尔选择性为85.6%。通过红外光谱对H3PW12O40和H3PW12O40/SiO2催化剂的结构进行研究,发现催化剂基本保持杂多酸的Keggin结构。     

Acrolein formation in the oxidation of ethane over silica catalysts supporting iron and cesium

A significant yield of aldehydes was obtained by the partial oxidation of ethane over alkali‐modified Fe/SiO₂ catalysts at 475°C (<2% in the case of Cs–Fe/SiO₂). Not only acetaldehyde and formaldehyde but also acrolein were produced in the present system. There are no reports regarding the catalysts for the direct acrolein formation from partial oxidation of ethane. Such significant promoting effect of alkali‐modified Fe/SiO₂ catalysts in the partial oxidation of hydrocarbons has never been observed. Aldol‐type condensation for formation of acrolein could occur in the partial oxidation of ethane over alkali‐modified Fe/SiO₂ catalysts. This revised version was published online in July 2006 with corrections to the Cover Date.     

New Insights in the Pathogenesis of Multiple Sclerosis—Role of Acrolein in Neuronal and Myelin Damage

Multiple sclerosis (MS) is an autoimmune disease of the central nervous system (CNS) characterized by an inappropriate inflammatory reaction resulting in widespread myelin injury along white matter tracts. Neurological impairment as a result of the disease can be attributed to immune-mediated injury to myelin, axons and mitochondria, but the molecular mechanisms underlying the neuropathy remain incompletely understood. Incomplete mechanistic knowledge hinders the development of therapies capable of alleviating symptoms and slowing disease progression in the long-term. Recently, oxidative stress has been implicated as a key component of neural tissue damage prompting investigation of reactive oxygen species (ROS) scavengers as a potential therapeutic option. Despite the establishment of oxidative stress as a crucial process in MS development and progression, ROS scavengers have had limited success in animal studies which has prompted pursuit of an alternative target capable of curtailing oxidative stress. Acrolein, a toxic β-unsaturated aldehyde capable of initiating and perpetuating oxidative stress, has been suggested as a viable point of intervention to guide the development of new treatments. Sequestering acrolein using an FDA-approved compound, hydralazine, offers neuroprotection resulting in dampened symptom severity and slowed disease progression in experimental autoimmune encephalomyelitis (EAE) mice. These results provide promise for therapeutic development, indicating the possible utility of neutralizing acrolein to preserve and improve neurological function in MS patients.     

Mo基复合金属氧化物催化丙烷氧化制丙烯醛

制备了Mo基复合金属氧化物(MoMxOn,M=C r,Co,Zn,Mn,Nb,Ce)催化剂,评价了不同金属含量的MoMxOn催化剂在不同温度下对丙烷选择性氧化制备丙烯醛反应的催化性能。在所研究的各种MoMxOn催化剂中,MoCo0.1On催化剂在773 K时的催化性能最佳,丙烯醛的收率为9.3%。Raman光谱和X射线衍射表征结果表明,除MoNbxOn催化剂外,其他各种MoMxOn催化剂中的主要物相是MoO3,说明MoO3可能对催化活性起重要作用。增加Co含量使MoO3衍射峰的相对强度发生改变,可能是引起MoCoxOn催化剂氧化性能下降的原因。     

金属氧化物对H_3PW_(12)O_(40)/γ-Al_2O_3在甘油制丙烯醛过程中性能的影响

采用分步等体积浸渍法制备了CeO2、La2O3、MgO、ZnO改性的PW/γ-Al2O3催化剂,用FTIR、XRD、BET、TG-DTA和活性评价等表征手段,考察了不同金属氧化物对PW/γ-Al2O3催化剂催化甘油脱水制丙烯醛反应性能的影响。结果表明:氧化物的引入,修饰了催化剂的表面性质,降低了催化剂的表面酸量。CeO2的添加,提高了催化剂的活性,尤其La2O3的添加,明显改善了催化剂的反应稳定性。而不同氧化物抑制积炭能力的强弱为:MgO>ZnO>La2O3>CeO2。     

丙烷均相氧化脱氢及其应用

丙烷在８００￣８４０Ｋ、Ｏ２／Ｃ３＾０比０．４４￣１．６５、停留时间６．０￣１３．５ｓ的条件下进行均相氧化脱氢。在丙烷转化率为４０％时，丙烯选择性为４２．５％，产率为１７．０％。用自丙烯生产丙烯醛的Ｍｏ－Ｃｏ－Ｒｅ－Ｂｉ－Ｏ催化剂，将上述反应产物在５９０￣６１５Ｋ、Ｏ２／Ｃ３＾０综合比０．６５￣１．１３、停留时间２．４￣４．２ｓ的条件下氧化，得到丙烯醛按丙烷衡算的选择性〉３３．５％，产率〉１３．５