کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4706241 1352996 2006 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
A combined FTIR and TPD study on the bulk and surface dehydroxylation and decarbonation of synthetic goethite
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات ژئوشیمی و پترولوژی
پیش نمایش صفحه اول مقاله
A combined FTIR and TPD study on the bulk and surface dehydroxylation and decarbonation of synthetic goethite
چکیده انگلیسی

The thermal dehydroxylation of a goethite–carbonate solid solution was studied with combined Fourier-transform infrared (FTIR)–Temperature programmed desorption (TPD) experiments. The TPD data revealed dehydroxylation peaks involving the intrinsic dehydroxylation of goethite at 560 K and a low temperature peak at 485 K which was shown to be associated to the release of non-stoichiometric water from the goethite bulk and surface. The FTIR and the TPD data of goethite in the absence of adsorbed carbonate species revealed the presence of adventitious carbonate mostly sequestered in the goethite bulk. The release of carbonate was however not only related to the dehydration of goethite but also from the crystallization of hematite at temperatures exceeding 600 K. The relative abundance of surface hydroxyls was shown to change systematically upon goethite dehydroxylation with a preferential stripping of singly-coordinated OH sites followed by a dramatic change in the dominance of the different surface hydroxyls upon the formation of hematite.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Geochimica et Cosmochimica Acta - Volume 70, Issue 14, 15 July 2006, Pages 3613–3624
نویسندگان
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