PdZnAl Catalysts for the Reactions of Water-Gas-Shift, Methanol Steam Reforming, and Reverse-Water-Gas-Shift

Journal Article · Fri Mar 07 04:00:00 EST 2008 · Applied Catalysis. A, General, 342(1-2):63-68

DOI:https://doi.org/10.1016/j.apcata.2008.03.005· OSTI ID:934874

Dagle, Robert A; Platon, Alexandru; Datye, Abhaya K; Vohs, John M; Wang, Yong; Palo, Daniel R

Pd/ZnO/Al2O3 catalysts were studied for water-gas-shift (WGS), methanol steam reforming, and reverse-water-gas-shift (RWGS) reactions. WGS activity was found to be dependent on the Pd:Zn ratio with a maximum activity obtained at approximately 0.50, which was comparable to that of a commercial Pt-based catalyst. The catalyst stability was demonstrated for 100 hours time-on-stream at a temperature of 3600C without evidence of metal sintering. WGS reaction rates were approximately 1st order with respect to CO concentration, and kinetic parameters were determined to be Ea = 58.3 kJ mol-1 and k0 = 6.1x107 min-1. During methanol steam reforming, the CO selectivities were observed to be lower than the calculated equilibrium values over a range of temperatures and steam/carbon ratios studied while the reaction rate constants were approximately of the same magnitude for both WGS and methanol steam reforming. These results indicate that although Pd/ZnO/Al2O3 are active WGS catalysts, WGS is not involved in methanol steam reforming. RWGS rate constants are on the order of about 20 times lower than that of methanol steam reforming, suggesting that RWGS reaction could be one of the sources for small amount of CO formation in methanol steam reforming.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 934874
• Report Number(s): PNNL-SA-58369; 19799; KC0302010
• Journal Information: Applied Catalysis. A, General, 342(1-2):63-68, Journal Name: Applied Catalysis. A, General, 342(1-2):63-68 Journal Issue: 1-2 Vol. 342; ISSN ACAGE4; ISSN 0926-860X
• Country of Publication: United States
• Language: English

Related Subjects

10 SYNTHETIC FUELS
CATALYSTS
Environmental Molecular Sciences Laboratory
KINETICS
METHANOL
PdZnAl catalyst
REACTION KINETICS
SINTERING
STABILITY
STEAM
fuel processing
methanol steam reforming
reverse-water-gas-shift
water-gas-shift (WGS)