کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5425447 | 1395856 | 2008 | 11 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
CO dissociation on Ni: The effect of steps and of nickel carbonyl
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: CO dissociation on Ni: The effect of steps and of nickel carbonyl CO dissociation on Ni: The effect of steps and of nickel carbonyl](/preview/png/5425447.png)
چکیده انگلیسی
The dissociation of CO was investigated on a stepped Ni(14Â 13Â 13) crystal. The experiments show that the monoatomic steps completely dominate the dissociation of CO on the nickel surface. The activation energy for dissociation of CO along the steps is measured at 500Â K to be 150Â kJ/mol in the pressure range 1-7Â ÃÂ 10â6Â mbar CO. Poisoning the steps by preadsorbing 0.05Â ML sulfur, the dissociation rate was reduced by more than a factor of 50 clearly providing evidence for the step activity. Furthermore, by deliberately adding remote amounts of nickel carbonyl (0.25%) to the CO gas, it is shown that the dissociation probability of CO is increased by a factor of 60 compared to when using a purified CO gas. This clearly demonstrates the importance of avoiding nickel carbonyl when CO dissociation is studied. CO dissociation is important because it is believed to be the rate limiting step in methanation and in the Fischer-Tropsch synthesis.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Surface Science - Volume 602, Issue 3, 1 February 2008, Pages 733-743
Journal: Surface Science - Volume 602, Issue 3, 1 February 2008, Pages 733-743
نویسندگان
Jakob Engbæk, Ole Lytken, Jane H. Nielsen, Ib Chorkendorff,