کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1329308 978904 2009 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Thermal, solution and reductive decomposition of Cu–Al layered double hydroxides into oxide products
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی معدنی
پیش نمایش صفحه اول مقاله
Thermal, solution and reductive decomposition of Cu–Al layered double hydroxides into oxide products
چکیده انگلیسی

Cu–Al layered double hydroxides (LDHs) with [Cu]/[Al] ratio 2 adopt a structure with monoclinic symmetry while that with the ratio 0.25 adopt a structure with orthorhombic symmetry. The poor thermodynamic stability of the Cu–Al LDHs is due in part to the low enthalpies of formation of Cu(OH)2 and CuCO3 and in part to the higher solubility of the LDH. Consequently, the Cu–Al LDH can be decomposed thermally (150 °C), hydrothermally (150 °C) and reductively (ascorbic acid, ambient temperature) to yield a variety of oxide products. Thermal decomposition at low (400 °C) temperature yields an X-ray amorphous residue, which reconstructs back to the LDH on soaking in water or standing in the ambient. Solution decomposition under hydrothermal conditions yields tenorite at 150 °C itself. Reductive decomposition yields a composite of Cu2O and Al(OH)3, which on alkali-leaching of the latter, leads to the formation of fine particles of Cu2O (<1 μm).

SEM image of (a) the Cu2O–Al(OH)3 composite obtained on reductive decomposition of CuAl4-LDH and (b) Cu2O obtained on leaching of Al(OH)3 from (a).Figure optionsDownload as PowerPoint slide

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Solid State Chemistry - Volume 182, Issue 5, May 2009, Pages 1193–1199
نویسندگان
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