Reaction pathways and structural requirements in the catalytic oxidation of methane at low temperatures

Conference · Tue Oct 01 04:00:00 EDT 1996

OSTI ID:370164

Fujimoto, K; Ribeiro, F H; Bell, A T ^[1]

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1. Univ. of California, Berkeley, CA (United States)

Methane oxidation turnover rates range from 0.030 to 0.16 s{sup -1} at 553 K on supported Pd/ZrO{sub 2} catalysts with Pd dispersions between 10.7 and 38.1%. Turnover rates increase with decreasing Pd dispersion for catalyst compositions and reaction conditions used in our studies. Steady-state turnover rates are reached after an initial induction period on samples prepared by rapid heating of Pd precursors in air. H{sub 2}-O{sub 2} titration and CO oxidation rate measurements show that the number of Pd or PdO atoms exposed at crystallite surfaces do not increase during activation. Changes in methane oxidation rates observed during this activation period apparently arise from modifications in surface structure caused by catalytic methane oxidation but not detected by structure-insensitive O{sub 2} chemisorption and CO oxidation reactions. Controlled decomposition of Pd precursors during catalyst synthesis eliminates induction periods and leads to the rapid attainment of steady-state turnover rates during methane oxidation.

• OSTI ID: 370164
• Report Number(s): CONF-960376--
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
CATALYTIC EFFECTS
CHEMISORPTION
METHANE
OXIDATION
PALLADIUM
SURFACES
ZIRCONIUM OXIDES