Decomposition pathways of C2 oxygenates on Rh-modified tungsten carbide surfaces

作者：Kelly Thomas G; Ren Hui; Chen Jingguang G^*

来源：Surface Science, 2015, 640: 89-95.

DOI：10.1016/j.susc.2015.03.008

• Ethanol
• Acetaldehyde
• Tungsten carbide
• Rh-modified tungsten carbide

Ethanol decomposition on tungsten monocarbide (WC) and Rh-modified WC was investigated using ultrahigh vacuum (UHV) surface science experiments and density functional theory (DFT) calculations. DFT calculations indicated that the binding energies of ethanol and its decomposition intermediates on WC(0001) were modified by Rh, with Rh/WC(0001) showing similar values to those on Rh(111). Through temperature-programmed desorption (TPD) experiments on polycrystalline WC and Rh-modified WC, it was shown that the selectivity for ethanol decomposition was different on these surfaces. On WC, the C-O bond of ethanol was preferentially broken to produce ethylene; on Rh-modified WC, the C-C bond was broken to produce carbon monoxide and methane. Furthermore, high-resolution electron energy loss spectroscopy (HREELS) was used to determine likely surface intermediates. On Rh-modified WC, ethanol first formed ethoxy through O-H scission, then reacted through an aldehyde intermediate to form the Cl products.

• 出版日期2015-10