Preparation of Pt/beta zeolite–Al2O3/cordierite monolith for automobile exhaust purification

A two-step route was developed to prepare zeolite beta coatings on structured monolith. Al2O3 layer was deposited on cordierite substrate by slurry dip-coating in the first step and beta zeolite layer was then coated on Al2O3/cordierite by direct dynamic hydrothermal synthesis in the second step. The as-prepared beta zeolite–Al2O3/cordierite was characterized by means of XRD and SEM techniques and the stability of beta coatings was studied. Based on these results, the advantages of the two-step method were discussed. After the introduction of Pt to beta zeolite–Al2O3/cordierite, the obtained Pt/beta zeolite–Al2O3/cordierite monolith was tested as promising catalyst for the purification of automobile exhaust from real lean-burn engine.