Selective hydrogenation of α,βα,β-unsaturated ketone to α,βα,β-unsaturated alcohol on gold-supported iron oxide catalysts: Role of the support

Milone, Candida; Ingoglia, R.; Schipilliti, Luisa; Crisafulli, C.; Neri, G.; Galvagno, S.

doi:10.1016/j.jcat.2005.09.023

Cited by 157 publications

(130 citation statements)

References 17 publications

Supporting

Mentioning

112

Contrasting

Unclassified

Order By: Relevance

“…According to the literature (Ilieva et al 1997;Neri et al 1999;Boccuzzi et al 1999;Minico et al 2000;Venugopal et al 2003;Hua et al 2004;Khoudiakov et al 2005;PalDey et al 2005;Milone et al 2005Milone et al , 2007Silberova et al 2006;Albonetti et al 2010), the peak at *400°C for Fe doped sample can be attributed to the reduction of hematite (Fe 2 O 3 ) to magnetite (Fe 3 O 4 ), while the peak at *600°C arises from the reduction of Fe 3 O 4 to FeO (wustite) and finally the peak at *850°C is assigned to the reduction to Fe. Three main peaks corresponding to the those reductions were obtained at similar temperatures (Table 2), being the first more intense.…”

Section: Temperature Programmed Reductionmentioning

confidence: 90%

Gold on oxide-doped alumina supports as catalysts for CO oxidation

2011

View full text Add to dashboard Cite

The effect of doping a commercial alumina support with metal oxides of Ce, Co, Cu, Fe, La, Mg, Mn, Ni and Zn was investigated. Doped d-Al 2 O 3 samples were obtained by simple physical mixture (PM) of the alumina with the desired commercial oxide and by traditional impregnation of alumina with precursor salts of the same metals followed by calcination (IC). The metal load (7% wt.) was the same in both cases. Gold (1% wt.) was loaded using a liquid phase reductive deposition method. The obtained materials were characterized by adsorption of N 2 at -196°C, temperature programmed reduction, X-ray diffraction, energy-dispersive X-ray spectrometry and transmission electron microscopy. Both samples prepared by PM and IC showed a mixture of the d-alumina phase with the respective metal oxide, but the BET surface areas of the IC samples were, in general, higher than those of the PM materials. The particle size of the oxide phases were larger for the PM samples than for the IC materials. Nevertheless, catalytic experiments for CO oxidation showed that PM samples were much more active than IC. That could be explained by the size of gold nanoparticles, well known to be related with catalytic activity, that was lower in samples prepared by PM (7-16 nm) than by IC (11-17 nm). Gold was found to be in the metallic state. The most active samples were aluminas containing Zn and Fe prepared by PM that had the smallest gold nanoparticles sizes (7-13 and 8-12 nm, respectively) and had room temperature activities for CO conversion of 0.62 and 1.34 mol CO h -1 g Au -1 , respectively, which are larger than those found in the literature for doped c-alumina samples.

show abstract

Section: Temperature Programmed Reductionmentioning

confidence: 90%

Gold on oxide-doped alumina supports as catalysts for CO oxidation

2011

View full text Add to dashboard Cite

show abstract

“…Conventional reduction of these compounds by gaseous dihydrogen over many metal catalysts results in preferable hydrogenation of the C=C bond [1][2][3][4][5]. Recently, metallic gold dispersed on FeOOH or c-Fe 2 O 3 has shown a remarkable chemoselectivity in the reduction of the conjugated C=O bond in the a,b-unsaturated carbonyl compounds [6,7].…”

Section: Introductionmentioning

confidence: 99%

Reactivity of Alcohols in Chemoselective Transfer Hydrogenation of Acrolein over Magnesium Oxide as the Catalyst

Gliński

Ulkowska

2010

Catal Lett

View full text Add to dashboard Cite

This paper presents the first full thermodynamic description of the hydrogen transfer between acrolein, the simplest a,b-unsaturated aldehyde, and a set of aliphatic alcohols, both primary and secondary. The vapour phase transfer hydrogenation of acrolein into allyl alcohol with various primary and secondary aliphatic alcohols used as hydrogen donors in the presence of MgO as the catalyst has been studied. Despite differentiated reactivity exhibited by these alcohols, a high chemoselectivity ([80%) to allyl alcohol has been observed for all of them. On the basis of thermodynamic calculations it has been found that secondary alcohols as hydrogen donors are more reactive than primary ones. However, ethanol or butan-1-ol have shown the highest reactivity. In their presence yields of allyl alcohol higher than 60% have been noted, which greatly exceed those predicted by thermodynamic calculations based on the following equation: acrolein ? ethanol (butan-1-ol) ? allyl alcohol ? acetaldehyde (butyraldehyde). Although similar yields have been reported in literature, no subsequent nor side reactions have been discussed even though the attained yield cannot be accounted for by this reaction alone. As a possible explanation of the discrepancy the occurrence of a disregarded reaction, for which DG \ 0, has been considered. It has been shown that aldol condensation fulfills these thermodynamic requirements, however, the products of this reaction are noted only at the beginning of the process and the decrease of their amount does not influence the yield of allyl alcohol.

show abstract

“…It is interesting to note that after 1 h reduction of the catalyst in H 2 , at 343 K in ethanol (entry 11), the chemical state of iron oxide is substantially unmodified with respect to that of the "as prepared sample" [5]. Au(III), instead is converted to Au metal [6].…”

Section: Resultsmentioning

confidence: 99%

“…On this catalyst the support is present as crystalline hematite, ␣Fe 2 O 3 and gold is under metallic state [5,6]. Table 2 shows the preparation method, the gold loading and the total surface area (SA) of gold catalysts supported on iron oxy-hydroxides used in the oxidation of salycilic alcohol.…”

Section: Resultsmentioning

confidence: 99%

“…Ponec et al have reported that the rate of hydrogenation of the C=O bond of propanal is dramatically enhanced by addition of Sn(II), Ga(III) or Fe(III) to a Pt/SiO 2 catalyst, whereas the rate of hydrogenation of acetone is only hardly increased [20]. Selective hydrogenation of ␣,␤ unsaturated ketones to the corresponding unsaturated alcohols, with molecular H 2 , has been instead achieved on Au supported on iron oxyhydroxides catalysts [4][5][6]. In particular, in the hydrogenation of benzalacetone and 4-methyl,3-penten,2-one the selectivity towards the formation of unsaturated alcohol was higher than 60% up to quantitative conversion of the substrates.…”

mentioning

confidence: 99%

See 1 more Smart Citation