کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
9609756 46532 2005 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
A study of the deactivation by sulfur and regeneration of a model NSR Pt/Ba/Al2O3 catalyst
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی کاتالیزور
پیش نمایش صفحه اول مقاله
A study of the deactivation by sulfur and regeneration of a model NSR Pt/Ba/Al2O3 catalyst
چکیده انگلیسی
The deactivation by sulfur and regeneration of a model Pt/Ba/Al2O3 NOx trap catalyst is studied by hydrogen temperature programmed reduction (TPR), X-ray diffraction (XRD), and NOx storage capacity measurements. The TPR profile of the sulfated catalyst in lean conditions at 400 °C reveals three main peaks corresponding to aluminum sulfates (∼550 °C), “surface” barium sulfates (∼650 °C) and “bulk” barium sulfates (∼750 °C). Platinum plays a role in the reduction of the two former types of sulfates while the reduction of “bulk” barium sulfates is not influenced by the metallic phase. The thermal treatment of the sulfated catalyst in oxidizing conditions until 800 °C leads to a stabilization of sulfates which become less reducible. Stable barium sulfides are formed during the regeneration under hydrogen at 800 °C. However, the presence of carbon dioxide and water in the rich mixture allows eliminating more or less sulfides and sulfates, depending on the temperature and time. The regeneration in the former mixture at 650 °C leads to the total recovery of the NOx storage capacity even if “bulk” barium sulfates are still present on the catalyst.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Applied Catalysis B: Environmental - Volume 61, Issues 3–4, 9 November 2005, Pages 236-243
نویسندگان
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