糠醛气相加氢制备糠醇Cu/SiO2催化剂的失活机理研究

Deactivation mechanism of Cu/SiO2 catalyst in gas phase hydrogenation of furfural to furfuryl alcohol

  • 摘要: 采用共沉淀法制备了Cu/SiO2催化剂,在固定床反应器上评价其糠醛气相催化加氢制备糠醇的反应性能,并采用XRD、H2-TPR、ICP-OES、XPS、TG、Raman、TEM等手段对使用后的Cu/SiO2催化剂进行表征,研究其在反应中的失活机理。在常压、反应温度140 ℃、质量空速2.4 h−1、氢醛比9.7的条件下,反应5 h内糠醛转化率均高于97%;反应6−21 h,糠醛转化率从96%快速下降到32%,说明Cu/SiO2催化剂在糠醛加氢反应中快速失活,失活的主要原因是活性组分铜的团聚烧结和催化剂表面上积炭覆盖了反应活性位。

     

    Abstract: The Cu/SiO2 catalysts were prepared by co-precipitation and tested for hydrogenation of furfural to furfuryl alcohol in a fixed bed reactor. The deactivation mechanism of the catalysts was investigated by characterization of H2-TPR, ICP-OES, XPS, TG, Raman and TEM. Under the conditions of atmospheric pressure, reaction temperature of 140 ℃, mass space velocity of 2.4 h−1 and the molar ratio of hydrogen to furfural of 9.7, the furfural conversion was higher than 97% in the first 5 h. However, the conversion of furfural decreased rapidly from 96% to 32% after 21 h of reaction, indicating that Cu/SiO2 catalyst was rapidly deactivated. The factors for the deactivation of Cu/SiO2 catalyst were the agglomeration and sintering of the active component copper. Moreover, the carbon deposition on the catalyst surface resulted in the covered active site Cu0.

     

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