کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
62582 47646 2009 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Reversible changes in the Pt oxidation state and nanostructure on a ceria-based supported Pt
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی کاتالیزور
پیش نمایش صفحه اول مقاله
Reversible changes in the Pt oxidation state and nanostructure on a ceria-based supported Pt
چکیده انگلیسی

The Pt oxidation state and nanostructure on a ceria-based oxide support were characterized after sequential oxidative, reductive, and re-oxidative treatments using X-ray photoelectron spectroscopy and transmission electron microscopy. The Pt oxidation state and nanostructure depended on the treatment atmosphere: an oxidized Pt monolayer spread along the primary particle surface of the ceria-based oxide support in the oxidized catalyst, whereas metallic Pt existed as particles of 1–2 nm in diameter in the reduced catalyst. Therefore, on the ceria-based oxide surface oxidized Pt formed a nanocomposite oxide with Ce under an oxidative atmosphere and reversibly changed to metallic Pt particles under a reductive atmosphere. The formation of this surface nanocomposite oxide is evidence of the strong interaction between oxidized Pt and CeO2 that involves the formation of a Pt–O–Ce bond, which stabilizes Pt against sintering and redisperses agglomerated Pt particles under an oxidative atmosphere.

Depending on the treatment conditions, platinum on a ceria-based oxide support changes reversibly from a small metallic nanoparticle to an oxidized monolayer, providing evidence of Pt–O–Ce bond formation in the latter.Figure optionsDownload high-quality image (71 K)Download as PowerPoint slide

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Catalysis - Volume 266, Issue 2, 10 September 2009, Pages 182–190
نویسندگان
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