<p>Chromia-alumina catalytic aerogels are prepared via an epoxide-assisted sol-gel synthesis followed by a patented rapid supercritical extraction (RSCE) method, for potential application in automotive pollution mitigation. As-prepared materials have density 0.21 ± 0.3 g/mL and surface area ~570 m²/g; following heat-treatment to 800 °C, density increases to 0.30 g/mL and surface area decreases to ~150 m²/g. Physical characterization via several methods, including XRD and SEM, reveals that heat-treated chromia-alumina aerogels contain chromium(III) oxide microcrystals within an amorphous alumina backbone. Catalytic efficacy is evaluated using an in-house-constructed testbed in which the heat-treated aerogel materials are exposed to simulated automotive exhaust under temperature conditions that approximate those experienced in an automotive three-way catalytic converter. Chromia-alumina aerogels show significant three-way catalytic activity. They achieve light off (50% conversion) at 330 and 360 °C for hydrocarbon (propene) and CO, respectively, under simulated lean combustion (i.e., excess oxygen) conditions. With respect to NO they achieve light off by 355 °C under simulated rich combustion (i.e., excess fuel) conditions.</p> Graphical Abstract <p></p>