Catalytic Partial Oxidation of CH4 over Ni-substituted Barium Hexaaluminate catalysts

Journal Article · Sat Dec 31 04:00:00 EST 2011 · Catalysis Today

OSTI ID:1042183

Gardner, T; Spivey, J; Campos, A; Hissam, J; Kugler, E; Roy, A

Ba{sub 0.75}Ni{sub y}Al{sub 12-y}O{sub 19-{delta}} (y = 0.2, 0.4, 0.6, 0.8 and 1.0) catalysts were tested for the partial oxidation of CH{sub 4} at temperatures between 200 and 900 C. Temperature programmed reaction results indicate that light-off for the partial oxidation reaction occurred between 665 and 687 C for all catalysts. Isothermal runs performed at 900 C on the catalysts showed stable reaction product concentrations, consistent with equilibrium. Post-reaction analysis of the used catalysts showed that there are two distinct zones in the catalyst bed. In a short leading edge of the bed, the apparently complete consumption of oxygen leads to a catalyst which XANES analysis shows is primarily Ni-substituted into the hexaaluminate phase. In the downstream portion of the bed, Ni is shown to be present as metallic Ni. This corresponds to a reaction sequence in which the oxidation of CH{sub 4} proceeds at the inlet until all oxygen is reacted, followed by the reaction of CO{sub 2} and H{sub 2}O with unreacted CH{sub 4}, and its derivatives, to produce the final syngas mixture. From the change in the unit-cell dimensions with Ni substitution, there is a clear indication that Ni{sup 2+}, which has a larger ionic radius than aluminum, substitutes for Al{sup 3+} in the hexaaluminate lattice in the synthesis process, and there is no restructuring of the bulk hexaaluminate phase after the Ni is removed from the lattice.

• Research Organization: BROOKHAVEN NATIONAL LABORATORY (BNL)
• Sponsoring Organization: USDOE SC OFFICE OF SCIENCE (SC)
• DOE Contract Number: AC02-98CH10886
• OSTI ID: 1042183
• Report Number(s): BNL--97861-2012-JA
• Journal Information: Catalysis Today, Journal Name: Catalysis Today Journal Issue: 1-4 Vol. 157; ISSN 0920-5861; ISSN CATTEA
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
ALUMINIUM
BARIUM
CATALYSTS
DIMENSIONS
METHANE
NICKEL
OXIDATION
OXYGEN
SYNTHESIS