Engineering isolated Al2O3 island enables adjacent TiO2-supported Ir@Pt nanoparticles for efficient and sulfur-resistant lean methane oxidation

Sulfur-induced catalyst deactivation has been a challenge in the design of gaseous pollutants purified catalyst. As the mainstream strategy for anti-sulfur catalyst design, the incorporation of sacrificial components into the catalyst bulk still faces issues such as increased cost and rapid activity decline. Herein, the physical isolated island strategy is proposed to improve the sulfur resistance and cost-effectiveness of a lean methane oxidation catalyst at no cost of its high activity. The isolated Al 2 O 3 island suppresses the formation of sulfates on adjacent Ir@Pt nanoparticles and avoids the sulfation of Ir@Pt/TiO 2 . Meanwhile, the isolated Al 2 O 3 island draws little effect on the chemical states of active sites. The sulfur adsorption function of isolated Al 2 O 3 island and high activity of Ir@Pt/TiO 2 are synergistically combined, leading to both remarkably high CH 4 oxidation activity (TOF = 1.2 s ‒1 at 350 °C) and high sulfur resistance without observable activity loss during 50 h on-stream test under 50 ppm SO 2 and a space velocity of 30000 mL g ‒1 h ‒1 . Such isolated-island strategy provides a meaningful reference for the efficient sulfur resistance catalyst design.