Characterization and catalytic behavior of CuO@SiO2 nanocomposites towards NO oxidation and N2O decomposition

Abstract

Abstract A distinct concentration of copper was embedded into silica matrix to form xerogel using Cu(NO3)2 · 3H2O as the copper source. The xerogel samples were prepared by hydrolysis and condensation of tetraethyl orthosilicate (TEOS) by the sol–gel method. The new molar ratio of H2O/TEOS was determined to be 11.67. Also the necessary amount of trihydrated copper nitrate was added into the solution such that the concentration of the copper oxide in the final solution reached 10 wt.%. After ambient drying, the xerogel samples were heated to 100, 400, 600, 800, and 1000°C at a slow heating rate (50 K h−1). The structural properties were characterized by means of transmission electron microscopy, surface analysis and thermal program reduction methods at different temperatures. Finally, the catalytic behavior of nanocomposites was studied for nitrogen oxide (NO) oxidation and di-nitrogen oxide (N2O) decomposition reactions. The results present a systematic reactivity study of NO oxidation and N2O decomposition on the dispersed copper oxide nanocatalysts over silica supports in order to determine the ability of these materials to convert nitrogen oxide and di-nitrogen oxide into harmless species at different temperatures.