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Cerium carbonate

Kim and Thompson—site blocking by formates/carbonates over Au/ceria catalysts linked to deactivation. Kim and Thompson437 reported on the deactivation of Au/ceria catalysts. The ceria was prepared by the decomposition of cerium carbonate (BET SA ceria calcined at 400 °C = 203 m2/g) or obtained from Rhodia (BET SA ceria calcined at 400 °C = 155 m2/g). Au was added by precipitation of HAuC14, resulting in a particle distribution between 1 and 10 nm, with the majority of clusters between 2 and 7 nm, as examined by HR-TEM. The experimental catalyst was tested with respect to the Sud-Chemie water-gas shift catalysts, consisting of Cu-Zn-Al with surface area 60 m2/g, and results are reported in Table 87. [Pg.240]

Cerium-oxalate, -carbonate and -hydroxide are considered to be the most important precursors for cerium-derivatives on a commercial scale. The cerium derivatives are yielded from these compounds by additional chemical and/or physical treatment. For example, cerium oxide may be formed easily by calcining cerium carbonate or/and cerium oxalate respectively. [Pg.14]

Cerium carbonate (aq) Lethal dose. 50% killed oral Rodent-rat > 5000 rpg / kg [401... [Pg.19]

Derivation Action of sulfuric acid on cerium carbonate. [Pg.256]

Derivation Action of hydrochloric acid on cerium carbonate or hydroxide. [Pg.257]

Monocarbides. Brewer and Krikorian (1956) and Dancy et al. (1962) had reported the monocarbide of cerium, but its existence has been discredited. Spedding et al. (1958) found that the lattice parameter reported by Brewer and Krikorian (1956) for CeC was identical with that of Ce metal saturated with C, and the reported CeC was most likely a solid solution of C in Ce. Anderson et al. (1969) re-examined the binary cerium-carbon system, and gave no evidence for the existence of any phase structurally based on monoatomic (methanide) anions. [Pg.84]

Rare earth carbonates have few uses as such. They are used as a rare earth source in synthesis and in the preparation of microcrystalline oxide powders (Yukinori and Fumikazu, 1978). Cerium carbonates have been suggested for use in thermochemical cycles for the production of hydrogen from water (Peterson and Onstott, 1978). [Pg.233]

The thermal dissociation of praseodymium carbonate in an O2 atmosphere yields an intermediate tetravalent carbonate. This decomposes at much lower temperature (295-310°C) than tetravalent cerium carbonate (Pajakoflf, 1968). [Pg.241]

Dienones from a-subst. propargyl acetoacetates s. 13, 900 Cerium carbonate... [Pg.625]

Yin and co-workers used NaHCOj and NagCOj as precipitants to prepare plate-like cerium carbonate precursors (Fig. 6.5)."° After calcination at 400°C for 1 hour, ceria particles with the right shape were obtained. The particle size can be tuned by acyusting the pH value of the solution during precipitation. [Pg.307]

The opposite results were found by Aneggi et aL, ° who studied the influence of pore size distribution on three samples of ceria, with the same surface area but prepared by different methods (Table 11.2). CA was a commercial sample prepared by a proprietary method and calcined at 773 K. CB was prepared according to a process that involved the precipitation of a homogeneous acidic solution of cerium nitrate with a base. The CC sample was freshly prepared by moderate calcination (473 K) of cerium carbonate obtained from Ce(NOs)3 by precipitation with NH4HCOS. Samples CB and CC have a smaller pore size (5-6 nm) than CA (14 nm) and... [Pg.578]


See other pages where Cerium carbonate is mentioned: [Pg.219]    [Pg.205]    [Pg.271]    [Pg.256]    [Pg.257]    [Pg.850]    [Pg.42]    [Pg.61]    [Pg.66]    [Pg.66]    [Pg.63]    [Pg.398]    [Pg.7]    [Pg.501]    [Pg.543]   
See also in sourсe #XX -- [ Pg.221 ]




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