交联蒙脱土负载型Cu催化剂用于CH4燃烧反应的研究

交联蒙脱土负载型Cu催化剂用于CH4燃烧反应的研究

  • 摘要: 在蒙脱土原粉中引入Al-、AlZr-、AlCe-交联剂,分别制备交联蒙脱土。测试表明:与蒙脱土原粉相比,Al-、AlZr-、AlCe-交联蒙脱土的底面间距明显增大,热稳定性显著提高;AlZr-、AlCe-交联蒙脱土的底面间距比Al-交联蒙脱土更大,热稳定性更高。以交联蒙脱土为载体,制得负载型Cu催化剂,考察了它们对甲烷燃烧反应的催化活性。结果表明:AlZr-、AlCe-交联蒙脱土催化剂活性明显高于Al-交联蒙脱土催化剂,反应温度为550 ℃时,甲烷在AlZr-、AlCe-交联蒙脱土催化剂上的转化率约90%。

     

    Abstract: Montmorillonite, one kind of the natural clay, is a promising catalyst support, but its application under actual circumstance is limited due to the small basal spacing (d001) and the weak thermal stability. In the present research, one kind of raw montmorillonite, produced in Shandong Province of China, was pillared by oligomeric hydroxyl Al and AlM (M=Zr, Ce) cation with 20 mmol/g of (Al+M)/clay and changing M/Al ratio to make pillared-clay(PILC). The d001 of Al-PILC and AlM-PILC measured by X-ray diffraction is 1.86 nm~1.92 nm and remains near 1.80 nm even calcined at 500 ℃, while that of raw montmorillonite is only 1.53 nm, which suggests the basal spacing of PILC is enlarged and subsequently its thermal stability is improved by Al and AlM pillars. Copper catalysts supported on PILC were prepared and applied in the catalytic combustion of methane. The results show that the CH4 conversion over Cu catalysts supported on AlZr- or AlCe-PILC, which exceeds 90% at 550 ℃ of reaction temperature, is largely higher than that over Al-pillared catalysts.

     

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