کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
57160 | 47108 | 2009 | 9 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Solid-state kinetics and catalytic behavior of selective oxidation catalysts from time-resolved XAFS investigations
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کلمات کلیدی
Reduction - اکسایشOxides - اکسیدOxidation - اکسیداسیونSelective oxidation - اکسیداسیون انتخابیX-ray absorption - جذب اشعه ایکسIn situ - در سایتStructure–activity relationships - روابط ساختاری-فعالیتTime-resolved - زمان حل شدهsolid-state kinetics - سینتیک حالت جامدEXAFS spectroscopy - طیف سنجی EXAFSMolybdenum - مولیبدنومHeterogeneous catalysis - کاتالیست ناهمگن
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
کاتالیزور
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Solid-state kinetics and catalytic behavior of selective oxidation catalysts from time-resolved XAFS investigations Solid-state kinetics and catalytic behavior of selective oxidation catalysts from time-resolved XAFS investigations](/preview/png/57160.png)
چکیده انگلیسی
Time-resolved measurements are required to elucidate time-dependencies of the electronic and geometric structure of a catalyst under changing reaction conditions. Monitoring the evolution of the bulk structure of a catalyst under changing conditions reveals the solid-state kinetics of the corresponding reaction. X-ray absorption spectroscopy (XAS) permits to reveal quantitative phase composition and average valence together with the evolution of the local structure. Hence, combining time-resolved XAS with simultaneous catalysis measurements may elucidate correlations between catalytic performance, the catalyst state under reaction conditions, and its solid-state kinetics. Here, results from time-resolved in situ XAS investigations of various molybdenum-based selective oxidation catalysts are compared and discussed. Model systems (i.e. α-MoO3, hexagonal MoO3 supported on SBA-15, and H4[PVMo11O40]) suitable to distinguish structural effects and promotion by additional metal centers have been studied under changing reaction conditions. Correlations between reduction and oxidation solid-state kinetics and catalytic performance reveal the dependence of the selectivity of the catalyst on its electronic structure. In particular the re-oxidation kinetics and the average valence under reaction conditions appear to be determined by the defect structure of the underlying catalyst bulk.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Catalysis Today - Volume 145, Issues 3â4, 30 July 2009, Pages 258-266
Journal: Catalysis Today - Volume 145, Issues 3â4, 30 July 2009, Pages 258-266
نویسندگان
T. Ressler,