Hydrogenation of crotonaldehyde on Pt/TiO2 catalysts: Influence of the phase composition of titania on activity and intramolecular selectivity

Chemoselective hydrogenation of carbonyl compounds over heterogeneous catalysts

“…The increasing selectivity to crotyl alcohol with increasing conversion of crotonaldehyde over Pt/TiO 2 was interpreted by competitive adsorption, whereas the stable selectivity as a function of crotonaldehyde conversion was obtained over Pt/anatase. In this case butyraldehyde was the most dominant product [157]. It was proposed that butyraldehyde is formed on metallic Pt sites, whereas crotyl alcohol is formed on special sites exhibiting SMSI effect.…”

“…TiO 2 [12,13,16,22,30,37,38,49,70,72,77,80,89,91,99,114,123,155], CeO 2 [13,37,65,66,112,113], WO 3 , MoO 3 [34] and ZrO 2 [5,97] have been used in chemoselective hydrogenations. The use of reducible supports, like TiO 2 or Nb 2 O 5 , has increased the selectivity towards unsaturated alcohols [157]. The effect achieved by reducing a metal supported on reducible oxide at high temperature is called strong support metal interaction (SMSI).…”

“…22) and over Ti 4 Co 12 [188]. The support selection can, however, change the selectivityconversion relationship also in gas phase hydrogenation [157], indicating that different supports exhibit different adsorption strengths towards different compounds. This was the case in crotonaldehyde hydrogenation over Pt/rutile and Pt/anatase in crotonaldehyde hydrogenation, where Pt/rutile favored decreasing selectivity to crotyl alcohol with increasing conversion, whereas constant selectivity or Fig.…”

Structural Properties of Ag/TiO2 Catalysts for Acrolein Hydrogenation

“…With high-temperature reduced titania-supported platinum catalysts an increase of both the activity per gram of Pt and the specific activity, expressed as TOF, was observed for the hydrogenation of acetone 49 and crotonaldehyde. 50 Moreover, also the selectivity to the allylic alcohol 50,51 was increased in the hydrogenation of the latter, and it was argued that high-temperature reduction of Pt/TiO 2 creates special active sites (Ti 3+ , oxygen vacancies) at the Pt metal/support interface which can activate the CdO group. This was supported by equal activation energies for LTR and HTR platinum catalysts, suggesting that the higher activity of the HTR catalysts is due to an increase in the number of active sites.…”

Selective Hydrogenation of Cinnamaldehyde over Pt/ZrO2 Catalyst Modified by Cr, Mn, Fe, Co and Ni

“…Suitable carriers such as carbon, clay, alumina, silica, zirconia, titania supported platinum catalysts have been reported for the hydrogenation of a, b-unsaturated aldehyde. Metals deposited on reducible oxide TiO 2 and ZrO 2 show better catalytic behavior on the selective hydrogenation of chloronitrobenzene and a, b-unsaturated aldehydes [16][17][18][19][20][21][22][23]. It is proposed that the strong metal/support interaction is responsible for this behavior.…”