DeNOx activity of Ag/γ-Al2O3 nanocomposites prepared via the solvothermal route

Ag/gamma-Al(2)O(3) with silver loading of 3 wt.% were prepared by the solvothermal-calcination reaction of AgNO(3) in mixed water-alcohol solutions at 50-250 degrees C for 0-120 min, followed by calcinations at 550 degrees C for 2 h using gamma-Al(2)O(3) (SSA: 120-409 m(2) g(-1)), gamma-AlOOH (SSA: 270 m(2) g(-1)), Al(OH)(3) (SSA 10 m(2) g(-1)), Al(OCH(CH(3))(2))(3) and Al(NO(3))(3) as an aluminum source. The resultant product produced by the solvothermal reaction was Ag/gamma-AlOOH even though a different aluminum source was used and Ag/gamma-AlOOH was converted to Ag/gamma-Al(2)O(3) by the following calcinations. However, the characteristics of them changed greatly depending on the alumina source. The deNO(x) catalytic performance of Ag/gamma-Al(2)O(3) also greatly changed depending on the aluminum precursor and solvothermal solvent in the order gamma-AlOOH = gamma-Al(2)O(3) >> Al(OCH(CH(3))(2))(3) >> Al(NO(3))(3) > Al(OH)(3) and methanol = ethanol > 1-propanol > butanol >> hexanol, since the amount and size of silver particle impregnated and specific surface area of the product changed markedly. Ag/gamma-Al(2)O(3) prepared by solvothermal-calcination method consisted of homogeneously dispersed fine particles of silver and showed better performance for NO(x) decomposition than that by conventional impregnation-calcination method.