Design and Synthesis a Novel Supported Pd-Pt Mesoporous Composite as Catalysts for the Polyaromatic Hydrogenation

Abstract

Hydrothermally stable mesoporous aluminosilicates with tubular morphology and hexagonal nanochannels were prepared by a new route. The route is different from conversational method of highly ordered MCM-41 assembled from Beta zeolite seed colloidal. The synthesis of Beta zeolite-like seeds is a novel route of acid treatment. The XRD results indicated that the synthesized materials were well-ordered hexagonal mesostructures of MCM-41. The highly regular hexagonal mesostructures could survive by steaming at 750 °C for 2 h, exhibiting good hydrothermal stability. Combining the SEM investigation, the as-made materials showed tubular morphology with diameter of 0.4 μm. The sample has a stronger acid strength, and was used as the support of a Pd-Pt catalyst for the polyaromatics hydrogenation. It has high activity and good sulfur tolerance towards hydrogenation of aromatics of smaller diameter. It was demonstrated that the introduction of building units of Beta zeolite enhances the activity of polyaromatics hydrogenation. It can be concluded that the pore structure and acidity of support is a key factor for the design of a sulfur tolerant noble metal catalyst for aromatics saturation of diesel.