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.