Potential Application of Tungsten Carbides as Electrocatalysts. 2. Coadsorption of CO and H₂O on Carbide-Modified W(111)

Abstract

The decomposition of water and CO over clean and carbide-modified W(111) is studied by using temperatureprogrammed desorption (TPD), high-resolution electron energy loss spectroscopy (HREELS), and auger electron spectroscopy (AES). On both clean and modified W(111) surfaces, the activity toward the decomposition of water is found to be significantly higher than Pt group metals. For the CO experiments, both molecular and dissociative adsorption are observed on W(111) and C/W(111). Approximately 52% and 10% of the adsorbed CO dissociates to produce atomic oxygen and carbon on W(111) and C/W(111), respectively. In contrast, CO molecules undergo reversible desorption on oxygen-modified C/W(111) at temperatures as low as 242 K. Finally, coadsorption experiments of water and CO on C/W(111) show that the presence of surface hydroxyls hinders the adsorption of CO, and that only trace amount of gas-phase CO 2 is detected.

A Combined Surface Science and Electrochemical Study of Tungsten Carbides as Anode Electrocatalysts

“…Vibrational studies using HREELS have been performed to further understand the reactions of CH 3 OH, H 2 O and CO on the various surfaces discussed above [1][2][3][4][5][6][7][8]. For example, Fig.…”

“…Recently our group has published a series of papers on surface science and electrochemical studies aimed at evaluating the feasibility of using tungsten carbides as fuel cell anode electrocatalysts for direct methanol fuel cell (DMFC) [1][2][3][4][5][6][7][8]. In this manuscript we will provide an overview of these studies, as well as some recent results on this subject.…”

Transition Metal Carbides and Nitrides as Electrode Materials for Low Temperature Fuel Cells

“…Another theory for CO tolerance was proposed by Hwu et al for WC [80,81]. They suggested that the CO tolerance might be originated from the lower CO desorption temperature on pure and Pt modified WC than that of pure Pt.…”

Investigation of Pt/WC/C catalyst for methanol electro-oxidation and oxygen electro-reduction

“…WC has attracted much interest due to its special properties of Pt-like behaviour in some reactions [18] and insolubility in acid solutions [19]. Hwu et al [20][21][22] have reported that WC can be a potential alternative to the Pt catalyst due to its ability to dissociate 0378-7753/$ -see front matter © 2008 Elsevier B.V. All rights reserved. doi:10.1016/j.jpowsour.2008.07.067 methanol and desorb CO at relatively low temperatures.…”