Ni-Ti Intercalated and Supported Bentonite for Selective Hydrogenation of Cinnamaldehyde
Yiyuan Xu1, Tongming Su1, Xuan Luo1
1School of Chemistry and Chemical Engineering, Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, Guangxi University, 100 Daxue Road, Nanning, 530004, P. R. China.
Abstract:
Ni-Ti intercalated bentonite catalysts (Ni-Ti-bentonite) and Ni-TiO2 supported bentonite catalysts (Ni-TiO2 /bentonite) were prepared, and the effects of Ni-Ti supported and intercalated bentonite on the selective hydrogenation of cinnamaldehyde were investigated. Ni-Ti intercalated bentonite enhanced the Brønsted acid sites strength, decreased the acid amount and Lewis's acid sites strength, which inhibited the activation of the C=O bond and contributed to selective hydrogenation of the C=C bond. When Ni-TiO2 was supported on bentonite, the acid amount and Lewis's acid strength of the catalyst increased, providing additional adsorption sites and increased the acetals byproducts. Due to the higher surface area, mesoporous volume, and suitable acidity, compared with Ni-TiO2 /bentonite in methanol solvent, 2 MPa, 120 °C for 1 h, Ni-Ti-bentonite exhibited a higher cinnamaldehyde (CAL) conversion of 98.8 %, as well as a higher hydrocinnamaldehyde (HCAL) selectivity of 95 %, and no acetals were found in the product.
Related Concept Videos
Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation
Like alkenes, alkynes can be reduced to alkanes in the presence of transition metal catalysts such as Pt, Pd, or Ni. The reaction involves two sequential syn additions of hydrogen via a cis-alkene intermediate.
Reduction of Alkenes: Catalytic Hydrogenation
Metals like palladium, platinum, and nickel are commonly used in their solid forms — fine powder on an inert surface. As these catalysts remain insoluble in the reaction mixture, they are referred to as heterogeneous catalysts.
The hydrogenation process takes place on the...
Radical Substitution: Hydrogenolysis of Alkyl Halides with Tributyltin Hydride
The bonds formed in this reaction are stronger than the bonds broken, making it energetically favorable. The reaction follows a radical chain mechanism similar to radical halogenation...
Reduction of Benzene to Cyclohexane: Catalytic Hydrogenation
Alkynes to Aldehydes and Ketones: Acid-Catalyzed Hydration
Analogous to alkenes, alkynes also undergo acid-catalyzed hydration. While the addition of water to an alkene gives an alcohol, hydration of alkynes produces different products such as aldehydes and ketones.


