Citral hydrogenation over Ir/TiO2 and Ir/TiO2/SiO2 catalysts

Rojas, Hugo; Borda, Gloria; Reyes, Patricio; Martínez, José Javier Pérez-Fadón; Valencia, Jesús; Fierro, J.L.G.

doi:10.1016/j.cattod.2007.12.109

Cited by 41 publications

(25 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Furthermore, the effects of the support on the physical-chemistry properties of the platinum catalysts were studied based on the characterization results of X-ray diffraction (XRD), nitrogen physisorption at 77 K, hydrogen chemisorption at 298 K, temperature-programmed reduction of hydrogen (H 2 -TPR) and temperature-programmed desorption of ammonia (NH 3 -TPD). 12,13 , which affirmed that the platinum present high hydrogenate powder and because it is noble metal with high coste. The impregnated solids were dried at 393K for 6 h, calcined in air at 673 K for 2 h.…”

Section: Introductionmentioning

confidence: 78%

LIQUID-PHASE HYDROGENATION OF m-DINITROBENZENE OVER PLATINUM CATALYSTS

Rojas

Borda

Reyes³

et al. 2011

J. Chil. Chem. Soc.

View full text Add to dashboard Cite

The m-dinitrobenzene hydrogenation to m-phenylenediamine in liquid phase was studied with platinum supported on SiO 2 , TiO 2 , Al 2 O 3 and Nb 2 O 5 catalysts. Incipient impregnation method was used to prepare the catalysts with 1wt% of Pt. The effect of the support and the reduction temperature (473 K or 773 K) were analyzed. The materials were characterized by X-ray diffraction (XRD), nitrogen physisorption (77 K), hydrogen chemisorption (298 K), transmission electron microscopy (TEM), temperature programmed reduction (H 2 -TPR) and temperature programmed desorption of ammonia (NH 3 -TPD). The results showed that Pt/ TiO 2 (HT) catalyst had a higher yield (60%) toward m-phenylenediamine and conversion level (98.2%) of m-dinitrobenzene. This behavior can be attributed to the reduction of PtO x crystallites to metallic Pt, small particle size and the strong metal-support interaction due to the migration of TiO x species on the Pt crystallites.

show abstract

Section: Introductionmentioning

confidence: 78%

LIQUID-PHASE HYDROGENATION OF m-DINITROBENZENE OVER PLATINUM CATALYSTS

Rojas

Borda

Reyes³

et al. 2011

J. Chil. Chem. Soc.

View full text Add to dashboard Cite

show abstract

“…Hydrogenation of citral gives valuable products, including citronellal, geraniol, nerol, and citronellol. Hydrogenation of citral has been studied using Ru [4][5][6][7][8][9], Pt [7,[10][11][12][13][14][15], Pd [7,16,17], Rh [6,7,11], Au [18], Ni [6,7,19,20], Ir [7,[21][22][23], Co [7], Os [7], Ag [24] and bimetallic [12,21,[25][26][27][28][29] catalysts. Citral contains three double bonds of which two are conjugated (C=O and C=C) and the third is isolated.…”

Section: Introductionmentioning

confidence: 99%

Hydrogenation of Citral Over Carbon Supported Iridium Catalysts

et al. 2012

View full text Add to dashboard Cite

Hydrogenation of citral (3,7-dimethyl-2,6-octadienal) was carried out in a batch reactor at atmospheric hydrogen pressure and 70°C over Sibunit (mesoporous carbon) supported iridium catalysts with different metal loadings. The major products were isopropyl ethers of geraniol and nerol (2-propanol was used as solvent), but also geraniol, nerol, citronellal di-isopropyl acetal and citronellal were formed. The metal particle size was determined by CO-chemisorption and varied from 2 to 6 nm. The turnover frequency for hydrogenation reactions increased with the metal particle size.

show abstract

“…In the last few years fine chemical products obtained either selective hydrogenation or enantioselective hydrogenation to obtain chiral product has reached importance especially in the pharmaceutical industry [1][2][3][4][5][6] . The heterogeneous catalysis starts to develop in this area when Orito and coworkers reported the enantioselective hydrogenation of ethyl pyruvate to (R)-lactate on modified Pt with cinchonidine with an ee >95% 7 .…”

Section: Introductionmentioning

confidence: 99%

ENANTIOSELECTIVE HYDROGENATION OF ETHYL PYRUVATE IN FLOW REACTOR OVERPt-CD/Si0(2) CATALYSTS

Ruiz¹,

Reyes²

2008

J. Chil. Chem. Soc.

View full text Add to dashboard Cite

The continuous enantioselective hydrogenation of ethyl pyruvate (EP) in a continuous flow reactor at 25ºC on 1%Pt-CD/SiO 2 catalysts has been studied. The catalytic study included the analysis of variables such as: particle size, feed flow, H 2 pressure and the addition of chiral modifier to the reactor feed.The catalysts were prepared using impregnation of Pt colloids which are stabilized with different quantities of cinchonidine (CD) on SiO 2 . This process gives chiral properties to the catalyst and allows changing the particle size for the reaction of interest.The catalysts were characterized by adsorption/desorption isotherms of N 2 a 77 K, TEM, XPS and the analysis of products by GC-MS. The monitoring of the reaction indicates a significant increases in the conversion when decreasing the contact time and a maximum in the enantiomeric excess (ee) of 63 % to the (R)-ethyl lactate which is obtained after using 200mg of 1%Pt/SiO 2 catalyst (1.6nm) at 10 bar of H 2 and a flow of 0.3 mL/min of a mixture EP (0.01M) and CD (0.034M) in cyclohexane.

show abstract

Citral hydrogenation over Ir/TiO2 and Ir/TiO2/SiO2 catalysts

Cited by 41 publications

References 23 publications

LIQUID-PHASE HYDROGENATION OF m-DINITROBENZENE OVER PLATINUM CATALYSTS

LIQUID-PHASE HYDROGENATION OF m-DINITROBENZENE OVER PLATINUM CATALYSTS

Hydrogenation of Citral Over Carbon Supported Iridium Catalysts

ENANTIOSELECTIVE HYDROGENATION OF ETHYL PYRUVATE IN FLOW REACTOR OVERPt-CD/Si0(2) CATALYSTS

Contact Info

Product

Resources

About