کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1478087 991209 2006 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Nanoporous anatase ceramic membranes as fast-proton-conducting materials
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
Nanoporous anatase ceramic membranes as fast-proton-conducting materials
چکیده انگلیسی

Nanoporous anatase ceramic membranes were prepared via particulate sol–gel processes. The calcined xerogels were mesoporous, with a BET surface area of 121 m2/g, an average pore diameter of 5.8 nm and a pore volume of 0.236 cm3/g. Proton conductivity of the membranes was measured as a function of temperature and relative humidity, R.H. When anatase membranes are treated at pH 1.5, the proton conductivity increased in the whole range of temperature and R.H. It indicates that the surface site density (number of water molecules per square nanometer) of these materials has a strong effect on conductivity. The proton conductivity of the studied anatase membranes followed an Arrhenius-like dependence on the temperature (from room temperature to 90 °C), in both treated and untreated membranes. A sigmoidal dependence of the conductivity on the R.H. was observed with the greatest increase noted between 58 and 81% R.H. in both treated and untreated anatase membranes. The highest value of proton conductivity was found to be 0.015 S/cm at 90 °C and 81% R.H., for treated anatase ceramic membranes. An increase of the conductivity could be achieved by means of longer times of treatment.According to the activation energy values, proton migration in this kind of materials could be dominated by the Grotthuss mechanism in the whole range of R.H. The similar values of proton conductivity, lower cost and higher hydrophilicity of these membranes make them potential substitutes for perfluorosulfonic polymeric membranes in proton exchange membrane fuel cells (PEMFCs).

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of the European Ceramic Society - Volume 26, Issue 7, 2006, Pages 1231–1236
نویسندگان
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