Anchoring catalytically active species on alumina via surface hydroxyl group for durable surface reaction

Abstract

Ensuring durable catalyst structure is crucial for heterogeneous surface reactions. Particularly, exhaust gas treatment catalyst needs exceptional durability at very high temperature (≥ 800 ºC) and low-temperature activity. Here, a hierarchical catalyst structure consisting of alumina, ceria, and Pt was synthesized to achieve high activity and durability. The alumina surface was modified to have surface hydroxyl groups by hydrothermal pre-treatment at various temperatures, then this alumina was used to anchor catalytically active species to form a highly durable surface structure. Whereas Pt and ceria on bare alumina suffered from significant sintering after aging at 800 ºC, the same species formed on the pre-treated alumina hardly presented change in surface structure after aging. This durable Pt/CeO2/Al2O3 catalyst showed no degradation for the simultaneous oxidation of CO, C3H6, and C3H8 with water vapor for repeated reactions or long-term reactions. This work can provide a useful guideline in designing a durable heterogeneous catalyst.