کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
47563 46476 2009 5 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Poisoning of Pt/C catalysts by CO and its consequences over the kinetics of hydrogen chemisorption
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی کاتالیزور
پیش نمایش صفحه اول مقاله
Poisoning of Pt/C catalysts by CO and its consequences over the kinetics of hydrogen chemisorption
چکیده انگلیسی

The initial rate of hydrogen dissociation was studied as a function of irreversible CO coverage at 353 K on 30 wt.% Pt/carbon catalysts (Pt/C) prepared according to different processes. The Pt/C catalysts exhibit similar Pt dispersion (D ∼ 0.07) and mean Pt particles size (dp ∼ 16 nm). The turnover frequency (number of hydrogen molecules dissociated per CO-free surface Pt atom) was determined as a function of CO coverage from 0.0 to 0.8. The evolution of TOF as a function of CO coverage is in agreement with the model of CO adsorbing on low coordination sites (edges, corners) and then spreading across the faces to grow islands as Brandt suggested in the past (R.K. Brandt, M.R. Hughes, L.P. Bourget, K. Truszkowska, R.G. Greenler, Surf. Sci. 286 (1993) 15–25). At high CO coverage (∼0.8), TOF depends on the process by which the Pt/C catalyst was prepared. In particular, a Pt/C elaborated according to a colloidal process exhibits a low sensitivity to CO poisoning with an increase of TOF by one order of magnitude.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Applied Catalysis B: Environmental - Volume 92, Issues 3–4, 9 November 2009, Pages 280–284
نویسندگان
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