Porous Cu/Ce-K-O Nanocomposites for Simultaneous Removal of Soot and NOx from Diesel Exhaust Emission

The porous xCu/(1 - x)Ce-K-O (x = 0.1-0.4) nanocomposites were prepared by the citrate-gel thermal decomposition and reduction process. The effect of nanosized metallic Cu on their microstructure and catalytic properties was investigated by XRD, SEM, BET, TG analysis. With Cu content increasing, the grain size of metallic Cu is increased from 40 nm to 62 nm, whilst the grain size of CeO2 decreases from 38 nnn to 20 nm. While, their specific surface area (S-BET) and average pore size (P-ave) show an increasing trend with the Cu content increase in the nanocomposites. The catalytic activity for soot combustion is influenced by the Cu content, with a lowest T-20 (216 degrees C) and T-50 (357 degrees C) for xCu/(1 - x)Ce-K-O (x = 0.3) nanocomposite catalyst. The catalytic performance for the optimal xCu/(1 - x)Ce-K-O (x = 0.3) nanocomposite coated honeycomb ceramic device was evaluated under the practical diesel exhaust emissions at the temperature range of 200-400 degrees C. This 10 wt.% catalyst-loaded honeycomb ceramic device confirms a high catalytic activity and stability for simultaneous removal of soot and NOx, largely due to the porous structure and synergistic effect of nano Cu and nano ceria in the catalyst.