Co/Al2O3催化褐煤衍生模型化合物的加氢脱氧制单体烃类化合物

Catalytic hydrodeoxygenation of lignite-derived model compounds to monomeric hydrocarbons over Co/Al2O3

  • 摘要: 以钴铝类水滑石(CoAl-LDH)为前驱体,经焙烧和氢气还原制备了Co/Al2O3催化剂。采用X 射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)和X射线光电子能谱(XPS)等表征手段研究了前驱体及催化剂的理化性质。以2-萘基醚为褐煤模型化合物,考察了Co/Al2O3催化其加氢脱氧制单体烃的性能。结果表明,Co/Al2O3-700催化剂具有最高的加氢脱氧活性,在温度250 ℃和氢气压力2 MPa反应条件下,反应90 min时2-萘基醚完全转化为单体烃(十氢化萘和四氢化萘)。2-萘基醚先加氢生成6,6′-氧代二(1,2,3,4-四氢萘),然后断裂C−O键生成四氢化萘和5,6,7,8-四氢-2-萘酚是主要反应路径。此外,Co/Al2O3-700对褐煤衍生苄醚和苯醚模型化合物加氢脱氧同样具有很高的催化活性。

     

    Abstract: A Co/Al2O3 catalyst was synthesized by facile calcination and hydrogen reduction of a cobalt-aluminum hydrotalcite CoAl-LDH, and the X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photon spectroscopy (XPS) were used to characterize the physical and chemical properties of the precursor and catalysts. Using 2-naphthyl ether as the lignite derived model compound, the catalytic performance of Co/Al2O3 on the hydrodeoxygenation of 2-naphthyl ether to monomeric hydrocarbons was investigated. The results show that Co/Al2O3-700 has the highest hydrodeoxygenation activity. Under the conditions of 250 ℃, 2 MPa of initial H2 pressure and 90 min of holding time, the 2-naphthyl ether is completely converted to monomeric hydrocarbons (decalin and tetralin), in which the 2-naphthyl ether is first converted to 6,6'-oxybis (1,2,3,4-tetrahydronaphthalene) by hydrogenation and then the tetralin and 5,6,7,8-tetrahydronaphthalene-2-naphthol are formed by the cleavage of C−O bond. In addition, Co/Al2O3-700 also shows high activity for the hydrodeoxygenation of lignite-derived benzyl ether and phenyl ether model compounds.

     

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