Temperature-programmed reduction and CO hydrogenation of La[sub 2]O[sub 3]-promoted Rh/SiO[sub 2] catalysts

Journal Article · Tue Nov 30 23:00:00 EST 1993 · Journal of Catalysis; (United States)

DOI:https://doi.org/10.1006/jcat.1993.1344· OSTI ID:5224218

Borer, A L; Prins, R ^[1]

---

1. Laboratorium fuer Technische Chemie, Eidgenoessische Technische Hochschule, Zuerich (Switzerland)

Rh/SiO[sub 2]-, Rh/La[sub 2]O[sub 3]-, and La[sub 2]O[sub 3]-promoted Rh/SiO[sub 2] catalysts were investigated by temperature-programmed reduction (TPR) and CO hydrogenation. When the La[sub 2]O[sub 3]-Rh/SiO[sub 2] catalysts were prepared by sequential impregnation with La impregnation as the final step, the Rh particles were partly covered by La[sub 2]O[sub 3]. When the impregnation sequence was reversed, and also when coimpregnation was applied, well dispersed Rh particles were formed, which showed a distinct interaction with promoter but no covering. The presence of La[sub 2]O[sub 3] shifted the TPR reduction of Rh[sub 2]O[sub 3] to higher temperatures and enhanced the oxygenate selectivity in the CO hydrogenation. Catalysts exposed to air showed different TPR results and higher H[sub 2] consumptions than in situ calcined catalysts due to the presence of La carbonate. After removal of carbonate, on H[sup 2] consumption other than for the reduction of Rh[sup 3+] to Rh[sup o] was observed, demonstrating that no reduction of La[sup 2]O[sub 3] takes place. 44 refs., 7 figs., 3 tabs.

• OSTI ID: 5224218
• Journal Information: Journal of Catalysis; (United States), Journal Name: Journal of Catalysis; (United States) Vol. 144:2; ISSN 0021-9517; ISSN JCTLA5
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010408 -- Coal
Lignite
& Peat-- C1 Processes-- (1987-)
10 SYNTHETIC FUELS
100200 -- Synthetic Fuels-- Production-- (1990-)
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CATALYSIS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTIONS
ELEMENTS
HETEROGENEOUS CATALYSIS
HYDROGENATION
LANTHANUM COMPOUNDS
LANTHANUM OXIDES
METALS
OXIDES
OXYGEN COMPOUNDS
PLATINUM METALS
RARE EARTH COMPOUNDS
RHODIUM
SILICON COMPOUNDS
SILICON OXIDES
TRANSITION ELEMENTS