Supercritical Water Syntheses of Highly Active Composite Nano-Catalysts

X.L. Weng, Z.B. Wu, X.L. Weng
Zhejiang University, CN

Keywords: supercritical water, composite, catalyst, nano

Summary:

Herein, we explored a novel CHFS route using supercritical water for the synthese of highly active composite nano-catalysts, which yielded remarkably high near-surface dispersion of palladium and showed low-temperature activation of molecular oxygen with the total oxidation temperature for toluene removal at as low as 145 ºC. Such low T90 temperature for the catalysts containing 0.5-1 wt% palladium has not been reported before, where the vast majority being in the range of 200 - 300 °C. The unusual and rapid crystallizing environments of the CHFS route had also resulted in a strong metal−support interaction (SMSI) feature for its products, where the resulted Pt/CeO2 catalyst had formed –Ce4+–O2-–Pt2+– linkages, leading to the room-temperature oxidation of CO with the T90 at only 60 °C.