Temperature-programmed methanation on Pd/La[sub 2]O[sub 3] and Pd/SiO[sub 2] catalysts

Journal Article · Sat Oct 31 23:00:00 EST 1992 · Journal of Catalysis; (United States)

DOI:https://doi.org/10.1016/0021-9517(92)90024-C· OSTI ID:5517183

Kester, K B; Chen, B; Falconer, J L ^[1]

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1. Univ. of Colorado, Boulder, CO (United States)

Temperature-programmed reaction and desorption (TPR,TPD) spectra are compared for Pd/La[sub 2]O[sub 3] and Pd/SiO[sub 2] catalysts for CO methanation and CO and H[sub 2] coadsorption. A methoxy (CH[sub 3]O) species readily forms on the La[sub 2]O[sub 3] surface of Pd/La[sub 2]O[sub 3] by spillover, and this CH[sub 3]O hydrogenates to CH[sub 4] at a higher rate than CO adsorbed on Pd. Carbon also deposits on the catalyst surface during TPR, and then hydrogenates at a slower rate than CH[sub 3]O. In contrast, CH[sub 3]O does not form on Pd/SiO[sub 2] from CO and H[sub 2], and correspondingly Pd/SiO[sub 2] has a lower methanation activity than Pd/La[sub 2]O[sub 3]. Isotope labeling, interrupted reaction, activated adsorption, high-temperature TPD/TPR, and CH[sub 3]OH adsorption are used to study the surface processes on Pd/La[sub 2]O[sub 3]. The high methanation activity of Pd/La[sub 2]O[sub 3] catalysts during steady-state methanation may be related to the formation and hydrogenation of CH[sub 3]O. 28 refs., 12 figs., 1 tab.

• OSTI ID: 5517183
• Journal Information: Journal of Catalysis; (United States), Journal Name: Journal of Catalysis; (United States) Vol. 138:1; ISSN 0021-9517; ISSN JCTLA5
• Country of Publication: United States
• Language: English

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