Aerobic oxidation of 5-hydroxymethylfurfural (HMF) effectively catalyzed by a Ce_0.8Bi_0.2O_2−δ supported Pt catalyst at room temperature

Abstract

The oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) was efficiently catalyzed when Pt nanoparticles (NPs) were supported onto a Ce 0.8 Bi 0.2 O 2Àd solid solution. 98% yield of FDCA was achieved within 30 min at room temperature and the catalyst was reused five times without much loss of FDCA selectivity. It is the first report on the oxidation of HMF, an alcohol and an aldehyde, effectively catalyzed by a ceria-based material supported Pt catalyst. The individual properties of the Pt NPs and the ceria-based support were retained and not affected after their combination. The superior oxygen activation ability of the Bi-doped ceria thoroughly changed the performance of the ceria supported Pt catalyst. Pt NPs were responsible for the formation of the Pt-alkoxide intermediate, followed by b-H elimination with the help of hydroxide ions. Bi-containing ceria accelerated the oxygen reduction process because of the presence of a large amount of oxygen vacancies and the cleavage of the peroxide intermediate promoted by bismuth. These specific functions were well incorporated during the catalytic oxidation cycle, leading to the generation of the highly efficient Pt/Ce 0.8 Bi 0.2 O 2Àd catalyst for HMF oxidation at room temperature.Scheme 1 The oxidation of biomass-derived HMF to FDCA.

Metal Catalysts for the Efficient Transformation of Biomass‐derived HMF and Furfural to Value Added Chemicals

“…Similarly, Pt‐based catalysts have also shown higher catalytic performance for the oxidation reaction . Siankevich et al.…”

“…Similarly,P t-based catalysts have also shown higherc atalytic performance for the oxidation reaction. [206][207][208][209][210][211][212][213][214] Siankevich et al achieveda nefficient oxidation of HMF to FDCA over platinum nanoparticles coated with an imidazolium-based cross-linked polymeru sing oxygen as an oxidizing agent at 80 8Cu nder aqueous reaction conditions. [206] The study suggested that the counter anion of cationic polymer (chloride, BF 4 À ,P F 6 À ,b is(trifluoromethylsulfonyl)imide, hexanoate or laurateanions) affected the structure of Pt nanoparticles along with the surface electronic properties andt he catalytic activity.T he resultsinferred that bis(trifluoromethylsulfonyl)imide (weak nucleophilic anion) resulted in the highest reaction rates, which was assigned due to the weak interaction of polymer with the surface of nanoparticles and hence led to an ease access to the substrates.A nalogously,P tn anoparticles supported on functionalized carbon nanotubes (CNTs) have shown high performance towardsb ase-free aerobic oxidation of HMF to FDCA.…”

“…[207] These observations furthers uggested that the functional groups having oxygen atom especiallyc arbonyl/quinone and/or phenolg roups on the surface of CNT plays important role in the formation of FDCA, by facilitating the adsorption of HMF and otherr eaction intermediates and hence led to an enhance catalytic activity.A ne fficient oxidation of HMF to FDCA (98 % yield) was also reported over Ce 0.8 Bi 0.2 O 2-d supported Pt nanoparticles at room temperature. [214] Study revealed that Pt nanoparticlesr esulted to the generation of Pt-alkoxide intermediate that in the presence of OH À ion underwent b-H elimination (Figure 15). Furthermore, the presence of Bi in ceria enhanced the oxygen reduction, followed by the peroxide intermediate cleavage and facilitated the oxidation of HMF to FDCA under mild reaction conditions.…”

Catalytic Aerial Oxidation of Biomass‐Derived Furans to Furan Carboxylic Acids in Water over Bimetallic Nickel–Palladium Alloy Nanoparticles

“…Other than Au catalysts, Pt‐, Ru‐ and Pd‐based catalysts were also reported in the oxidation of 5‐HMF. In this direction, Pt‐based catalysts have exhibited high efficiency for the complete oxidation of 5‐HMF to FDCA, however, in the presence of a strong base and high pressure of O 2 or air . For example, recently Han et al.…”

“…also reported in the oxidation of 5-HMF.I nt his direction, Ptbased catalysts have exhibited high efficiency for the complete oxidation of 5-HMF to FDCA, however,i nt he presenceo f as trong base and high pressure of O 2 or air. [39,[48][49][50][51][52][53][54][55] [55] On the other side, Ru catalysts howed only partial oxidation of 5-HMF to DFF at 110 8Cw ith high pressure of O 2 , 2.0 MPa, using organic solvents. [56,57] Similarly to Au, Pd catalysts also showed high activity towards the oxidation of alcohols and carbonyl compounds.…”