PGM nanoparticle-based alumina aerogels for three-way catalyst applications

Alumina aerogels doped with PGM nanoparticles are prepared and characterized as candidates for three-way catalysts (TWCs). After heat-treatment at 800 °C the materials maintain low density (∼0.1 g/mL), high surface area (290–460 m2/g) and high pore volume (1.4–3.6 g/m3), but show some agglomeration of the nanoparticles. Pt-, Pd- and Rh-alumina aerogels show TWC activity comparable to a commercial catalyst. Light-off temperatures for CO and propene by Pd/Al2O3 aerogels are 190 and 220 °C (respectively) while for NO by Rh/Al2O3 aerogel is 250 °C. These materials are loaded at 0.08–0.16 g/L (2–3 g/ft3), considerably lower than typical TWC PGM loadings of 1.8–2.8 g/L (50–80 g/ft3).