Acetic Acid Reforming over Rh Supported on La2O3/CeO2-ZrO2: Catalytic Performance and Reaction Pathway Analysis

Journal Article · Thu Jul 11 04:00:00 EDT 2013 · ACS Catalysis

DOI:https://doi.org/10.1021/cs4003063· OSTI ID:1234801

Lemonidou, Angeliki A.; Vagia, Ekaterini C.; Lercher, Johannes A.

Reforming of acetic acid was investigated on Rh supported on CeO2-ZrO2 modified with 3 wt % La. The active catalyst converted acetic acid to H-2-rich gas and hardly formed coke. The low rate of coke formation is concluded to be related to the presence of redox-active oxygen limiting the concentration of coke precursors. Temperature-programmed O-18(2)) isotope exchange measurements showed that the La2O3 and Rh enhanced the mobility of lattice oxygen compared with that of the parent CeO2-ZrO2. Ketonization and decarboxylation of acetic acid are the dominating reactions over the latter up to 600 degrees C, whereas above 600 degrees C, steam reforming and water gas shift also contribute. Over 0.5 wt % Rh on La2O3/CeO2-ZrO2, reforming and water gas shift reactions dominate, even below 300 degrees C, producing mostly H-2 and CO2. Using isotope labeling, it is shown that acetic acid adsorbs dissociatively on Rh, forming acetates, which sequentially decarboxylate and form surface methyl groups. The latter are in turn converted to CO, CO2, and H-2.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1234801
• Report Number(s): PNNL-SA-100964
• Journal Information: ACS Catalysis, Journal Name: ACS Catalysis Journal Issue: 9 Vol. 3; ISSN 2155-5435
• Publisher: American Chemical Society
• Country of Publication: United States
• Language: English

Related Subjects

La2O3/CeO2-ZrO2
acetic acid
hydrogen production
steam reforming
supported Rh