کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9594485 | 1507963 | 2005 | 19 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Reaction of methyl formate with VC(1Â 0Â 0) and TiC(1Â 0Â 0) surfaces
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
The chemistry of the (1Â 0Â 0) surface of the tribologically important materials vanadium carbide (VC) and titanium carbide (TiC) with methyl formate (CH3OCHO) has been studied with X-ray photoelectron spectroscopy (XPS), high resolution electron energy loss spectroscopy (HREELS), and temperature programmed desorption (TPD). The molecule reacts with each surface at temperatures below 150Â K, although the extent of reaction is greater on the TiC surface. XPS and HREELS results indicate that the first step in this chemistry is the cleavage of the CH3O-CHO bond, generating surface methoxy groups (CH3O-) and either carbon monoxide on VC or a formyl (CHO) group on TiC. The methoxy group reacts further on both surfaces via pathways expected based on previous methanol adsorption studies, primarily decomposing through a formyl intermediate on VC to generate formaldehyde and evolving methanol on TiC. The formyl group formed directly from methyl formate on TiC enables the production and evolution of formaldehyde, and also appears to break down further to the elements. These results indicate a propensity for these carbides to react with esters, leading potentially to the beneficial formation of friction lowering surface films or the deleterious degradation of ester-based lubricants.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Surface Science - Volume 596, Issues 1â3, 10 December 2005, Pages 144-162
Journal: Surface Science - Volume 596, Issues 1â3, 10 December 2005, Pages 144-162
نویسندگان
Peter Frantz, Hyun I. Kim, Stephen V. Didziulis, Shuang Li, Zhiying Chen, Scott S. Perry,