Comparative DFT study on selective hydrogenation of acrolein catalyzed by pure Mo2C(001) and Pt/Mo2C(001)

In this paper, Density Functional Theory (DFT) calculations were conducted to study the adsorption and stepwise hydrogenation of acrolein (CH 2 =CHCH=O) on pure Mo 2 C(001) and Pt/Mo 2 C(001). The electronic properties were investigated by Mulliken population analysis. The results showed that Mo atoms obtained some electrons from surrounding Pt and C atoms, thereby enhancing the hydrogenation activity of Mo atoms around Pt atoms and forming local active sites dominated by Mo atoms around Pt atoms. As a result, the adsorption energy of the species on Pt/Mo 2 C(001) is generally higher than that on Mo 2 C(001), and the activation energies of the elementary reactions involved in stepwise hydrogenation of acrolein on Pt/Mo 2 C(001) are lower than those on Mo 2 C(001). Moreover, Pt/Mo 2 C(001) exhibits higher selectivity for C=O bond hydrogenation than Mo 2 C(001) and produces more allyl alcohol.

Zero-Valent Pd Atoms Anchored on Polyoxometalate for Low Temperature Hydrodeoxygenation

Single-atom catalysts usually comprise positively charged atomically dispersed metal cations on oxide supports. Neutral atoms on oxides are synthetically challenging, and their performance in catalytic reactions remains ambiguous. Here, we shed light on this question with the design of Pd single-atom catalysts on polyoxometalates. Depending on the composition of the support, Pd can either exhibit oxidation states of 0 or 2+. We show that this difference is decisive for the C-O bond hydrogenolysis while displaying negligible effects on the C=O bond hydrogenation. The selective conversion of 5-hydroxymethylfurfural (5-HMF) to 2,5-dimethylfuran (2,5-DMF), a key renewable fuel compound, was shown to occur at 253 K with reaction rates up to 71.0 per hour.<br>

Zero-Valent Pd Atoms Anchored on Polyoxometalate for Low Temperature Hydrodeoxygenation

Single-atom catalysts usually comprise positively charged atomically dispersed metal cations on oxide supports. Neutral atoms on oxides are synthetically challenging, and their performance in catalytic reactions remains ambiguous. Here, we shed light on this question with the design of Pd single-atom catalysts on polyoxometalates. Depending on the composition of the support, Pd can either exhibit oxidation states of 0 or 2+. We show that this difference is decisive for the C-O bond hydrogenolysis while displaying negligible effects on the C=O bond hydrogenation. The selective conversion of 5-hydroxymethylfurfural (5-HMF) to 2,5-dimethylfuran (2,5-DMF), a key renewable fuel compound, was shown to occur at 253 K with reaction rates up to 71.0 per hour.<br>

Heterogeneous palladium catalysts in the hydrogenation of the carbon-carbon double bond

: The results of studies over the past ten years in the field of C=C bond hydrogenation in the presence of palladium catalysts deposited on various inorganic and organic carriers such activated carbons, carbon nanotubes, alumina, zeolites, or composite materials based on Al2O3-SiO2, polystyrene, polypropyleneimine, polyamidoamine and hybrid inorganic/polymer carriers are presented. The selectivity and rates of the hydrogenation process are considered and some comparisons are made. Porous supports and containing dendrimers generally retain palladium particles more effectively. Nanosized palladium stabilized by different dendrimers catalyzes the hydrogenation of C=C bonds in polyfunctional compounds chemoselectively without affecting functional groups such as CHO, C=O, C(O)OR, CN, NO2, and halogens.

Facile synthesis of norbornene–ethylene–vinyl acetate/vinyl alcohol multiblock copolymers by the olefin cross-metathesis of polynorbornene with poly(5-acetoxy-1-octenylene)

New norbornene−ethylene–vinyl acetate/vinyl alcohol multiblock copolymers are synthesized via the olefin cross-metathesis reaction of polynorbornene with poly(5-acetoxy-1-octenylene) followed by CC bond hydrogenation and acetoxy group deprotection.

Catalytic Hydrogenation of Cinnamic Acid and Salicylic Acid

Hydrogenation of cinnamic acid and salicylic acid was carried out using 5 %Ru/C, 5 % Pd/C and Ru-Sn/Al2O3 catalyst at 493 K and 6.89 MPa of hydrogen partial pressure. Ru-Sn/Al2O3 catalyst was found to be active for hydrogenation -COOH group to give cinnamyl alcohol. The selectivity to cinnamyl alcohol was low (15 %) as absolute inhibition of C=C bond hydrogenation in cinnamic acid is challenging. 5 %Pd/C catalyst was found to hydrogenate C=C bond and aromatic ring in cinnamic acid. 5 %Ru/C catalyst was found to be least selective catalyst as it hydrogenated C=C bond, aromatic ring and -COOH group in cinnamic acid. Hydrogenation of salicylic acid is not possible at 493 K as decarboxylation of salicylic acid occurs.

Catalytic Performances of Platinum Containing PLLA Macrocomplex in the Hydrogenation of α,β-Unsaturated Carbonyl Compounds

The synthesis of a bipyridine poly(lactic acid) carboxylic end-capped macroligand coordinated to a platinum center was reported. The reaction between the metal ion and the polymeric ligand was run in a very efficient way through a one-step synthesis and the complex was tested for selective hydrogenation of α,β-carbonyl compounds. High selectivity was proven for double bond hydrogenation of 2-cyclohexen-1-one (up to 99%) and the production of 1-butanol from (E)-but-2-enal. Moreover, the catalytic system was still active after three catalytic cycles.