Porous Cu/Ce–K–O Nanocomposites for Simultaneous Removal of Soot and NO<SUB><I>x</I></SUB> from Diesel Exhaust Emission

Abstract

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 nm 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 T20 (216 degrees C) and T50 (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 NO(x), largely,due to the porous structure and synergistic effect of nano Cu and nano ceria in the catalyst.

Catalytic Soot Combustion─General Concepts and Alkali Promotion

“…Detailed data used for the compilation of Figure are reported in the Table , Table , and Table S1 in the Supporting Information. Depending on their chemical composition and morphology, the catalysts were divided into six groups: platinum metal group, ,− ceria–zirconia-based, − ,,,,,,,,,,− alkali-nanostructured, ,,,,− ,,,,,,,,− ,− spinel structure, ,,,,− ,,,− perovskite structure, ,,,,,,,,,…”