Boosting Removal of Diesel Soot Particles by Optimal Exposed Crystal Facet of CeO2 in Au/CeO2 Catalysts

Optimized surface facet of the catalysts is an efficient strategy to boost catalytic purification of diesel soot as important components of atmospheric fine particles. Herein, we have elaborately constructed the nanocatalysts of Au nanoparticles supported on the well-defined CeO2 (rod, cube, and polyhedron) with predominantly exposed facets of {110}, {100}, and {111}, respectively. The strong interaction between Au and CeO2 with the optimal crystal facet is crucial to adjust the active site density for activated O2, and the synergy effect of Au and the CeO2{110} facet possesses the largest density of active sites compared with other crystal facets of {100} and {111}. The catalytic activity for soot combustion was tuned by exposed crystal facets of CeO2. The Au/CeO2-rod catalyst exhibits the highest catalytic activity (T50 = 350 °C, TOF = 0.18 h–1) and the lowest apparent activation energy (72 kJ mol–1) during soot combustion. Based on the results of in situ Raman spectra, the formation and stability of ox...