Abstract
Au-based catalysts supported on carbon materials with different structures such as graphite (G) and fishbone type carbon nanofibers (CNF-F) were prepared using two different methods (impregnation and gold-sol) to be tested in the water gas shift (WGS) reaction. Atomic absorption spectrometry, transmission electron microscopy (TEM), temperature-programmed oxidation (TPO), X-ray diffraction (XRD), Raman spectroscopy, elemental analyses (CNH), N2 adsorption-desorption analysis, temperature-programmed reduction (TPR) and temperature-programmed decomposition were employed to characterize both the supports and catalysts. Both the crystalline nature of the carbon supports and the method of gold incorporation had a strong influence on the way in which Au particles were deposited on the carbon surface. The higher crystallinity and the smaller and well dispersed Au particle size were, the higher activity of the catalysts in the WGS reaction was noted. Finally, catalytic activity showed an important dependence on the reaction temperature and steam-to-CO molar ratio.
Highlights
Introduction5–20 vol% CO depending on the steam-to-carbon and air-to-fuel ratios in the feed
Different chemical reactions such as steam reforming (SRM) or autothermal reforming (ATR)of fuels produces a H2-rich fuel gas containing5–20 vol% CO depending on the steam-to-carbon and air-to-fuel ratios in the feed
The aim of this work was to study the catalytic activity for the Water Gas Shift (WGS) reaction of gold-supported catalysts, where the active metal was incorporated to carbon materials with different structural order: high crystalline graphite (G) and partially ordered fishbone carbon nanofibers (CNF-F)
Summary
5–20 vol% CO depending on the steam-to-carbon and air-to-fuel ratios in the feed. These reformates must be further processed to reduce the CO concentration because of the poisoning effect of CO in, for example, polymer electrolyte fuel cell (PEFC) applications. The Water Gas Shift (WGS) reaction (CO + H2O ↔ CO2 + H2; ∆H = −41.1 kJ/mol) is used in most fuel processing schemes to convert CO into CO2. There are four general types of water gas shift catalysts: promoted iron oxide catalysts for high temperatures (623–723 K), copper-zinc oxide catalysts for low temperatures (463–523 K), cobalt and molybdenum sulfides catalysts (sulfur-tolerant), and modified copper-zinc ones for medium temperatures (548–623 K) [1]. Pt, Rh, Ru, Au, and Pd deposited on partially reducible oxides (ceria [10,11,12], zirconia [13,14], titania [15], iron oxides [16], and mixed oxides such as ceria–zirconia) have been the most investigated
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
