Hydrothermally stable Pd/SiO2@Zr Core@Shell catalysts for diesel oxidation applications

Hydrothermally stable diesel oxidation catalysts (DOCs) with improved low-temperature activity are desired for the abatement of emissions from vehicles. Herein, novel palladium(Pd)/SiO2(core)@Zr(shell) structured DOCs were developed. SiO2 was completely covered by an 8.4 nm thickness Zr-based shell using a hard template method. The SiO2@Zr support decorated Pd and evaluated under simulated exhaust stream. Degreened 1 wt% Pd/SiO2@Zr achieved 90% CO total hydrocarbon conversion at 178 372 °C, respectively (feed: 6% CO2, 12% O2, H2O, 400 ppm H2, 2000 CO, 100 NO, 1667 C2H4, 1000 C3H6, 333 C3H8; HCs in C1 basis GHSV = 113,000 h?1). After hydrothermal aging, only minor deactivation observed, while surface area as high 104 m2/g. stability attributed to poor crystallinity SiO2@Zr, possibly due formation Si-O-Zr bonds. This work highlights promising potential utilizing durable applications.