Comparison of Reaction Pathways of Ethylene Glycol, Acetaldehyde, and Acetic Acid on Tungsten Carbide and Ni-Modified Tungsten Carbide Surfaces
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- 作者：Weiting Yu ; Zachary J. Mellinger ; Mark A. Barteau ; Jingguang G. Chen
- 刊名：The Journal of Physical Chemistry C
- 出版年：2012
- 出版时间：March 8, 2012
- 年：2012
- 卷：116
- 期：9
- 页码：5720-5729
- 全文大小：558K
- 年卷期：v.116,no.9(March 8, 2012)
- ISSN：1932-7455
文摘
Selectively converting biomass-derived oxygenates to H2 or syngas (H2 and CO) is critical in the utilization of biomass to replace fossil fuels. In previous studies, monolayer (ML) Ni on a Pt substrate showed enhanced conversion and selectivity for oxygenate conversion. In the current work, tungsten monocarbide (WC) is used to support monolayer Ni, with the aim of replacing ML Ni鈥揚t with ML Ni鈥揥C. C2 oxygenates with different functional groups, ethylene glycol, acetaldehyde, and acetic acid, are studied on clean WC and Ni-modified WC surfaces. For each C2 oxygenate, density functional theory (DFT) calculations reveal different binding energies on WC and Ni鈥揥C surfaces. Parallel experimental measurements using temperature programmed desorption (TPD) and high resolution electron energy loss spectroscopy (HREELS) confirm the different reaction pathways on the two types of surfaces, with the dominant decomposition pathway being C鈥揙 bond scission on clean WC and C鈥揅 bond cleavage on Ni-modified WC surfaces. Furthermore, using ethylene glycol decomposition as a probe reaction, the ML Ni鈥揥C surface exhibits a similar net reaction pathway as that of ML Ni鈥揚t(111).