Title of article :
Microwave-assisted synthesis of CuO/ZnO and CuO/ZnO/Al2O3 precursors using urea hydrolysis
Author/Authors :
Fernلndez، نويسنده , , Y. and Menéndez، نويسنده , , J.A. and Arenillas، نويسنده , , A. and Fuente، نويسنده , , E. and Peng، نويسنده , , J.H. and Zhang، نويسنده , , Z.B. and Li، نويسنده , , W. and Zhang، نويسنده , , Z.Y.، نويسنده ,
Issue Information :
هفته نامه با شماره پیاپی سال 2009
Pages :
7
From page :
1372
To page :
1378
Abstract :
Binary CuO/ZnO and ternary CuO/ZnO/Al2O3 catalysts have been rapidly synthesized in a multimode microwave oven by the homogeneous precipitation of aurichalcite and hydrotalcite-like precursors using urea hydrolysis. For purposes of comparison, the same catalysts were prepared under conventional heating. The corresponding metal nitrates were mixed with various amounts of urea to yield different urea/(ΣM+) molar ratios. The precipitation proceeded stepwise, copper being the first metal to be hydrolyzed. It was found that the higher the urea content, the higher the alkalinization of the solution, an effect which favored the precipitation of Zn (II) (the most pH dependent metal), and in turn, the synthesis of aurichalcite and hydrotalcite-like precursors. ave-synthesized catalysts presented similar characteristics to those obtained under conventional heating, but in considerably reduced aging times. Microwave radiation proved to be more efficient than conventional heating under harsh conditions of precipitation, i.e., lower molar ratios of urea with respect to the metal cations in the solution.
Keywords :
Aurichalcite , Cu-catalysts , Zn-catalysts , Urea hydrolysis , Microwave-heating , Hydrotalcite
Journal title :
Solid State Ionics
Serial Year :
2009
Journal title :
Solid State Ionics
Record number :
1721522
Link To Document :
بازگشت