Thermal and hydrothermal stability of siliceous Y zeolite and its application to high-temperature catalytic combustion

Abstract

Siliceous Y zeolite (SiO 2/Al 2O 3>150), prepared through repeated dealumination with SiCl 4 and steam, displays high thermal and hydrothermal stability. After aged at 1200°C for 4 h, siliceous Y zeolite shows specific surface area as high as 510 m 2/g. Even steamed at 1000°C for 4 h, it still keeps its framework perfectly. Palladium on siliceous Y zeolite shows a bit less oxidation activity of n-hexane than that on lanthanum–modified alumina. It exhibits good capability in resisting heat but poor resistance to steam. When palladium is supported on SY-A carrier, in which 12.3% alumina has been loaded on siliceous Y zeolite, the catalyst shows higher oxidation activity than Pd/La–Al 2O 3 even heated or steamed at 1000°C for 4 h. Its excellent resistances to heat and steam make it a promising catalyst for high-temperature catalytic combustion.