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

Abstract

Bimetallic Ni1−xPdx (0.10≤x≤0.75) alloy nanoparticle catalysts were synthesised and successfully employed for the catalytic aerial oxidation of biomass‐derived furans, such as 2‐furfuraldehyde (furfural), 2‐furfuryl alcohol (furfuryl alcohol), 5‐hydroxymethyl‐2‐furfural (5‐HMF), 5‐methyl‐2‐furfural (MF) and 5‐methyl‐2‐furfuryl alcohol (MFA), to selectively afford the corresponding furan carboxylic acids (2‐furoic acid, furan‐2,5‐dicarboxylic acid (FDCA) and 5‐methyl‐2‐furoic acid (MFCA)) in water at 80 °C. Among the studied Ni1−xPdx nanoparticle catalysts, Ni0.90Pd0.10 nanoparticle catalyst outperformed the others, achieving high yields of the corresponding furan carboxylic acid products. The presence of Ni in the Ni1−xPdx nanoparticle catalysts was advantageous, because it not only enhanced the catalytic activity for the facile oxidation of biomass‐derived furans using aerial oxygen to achieve high catalytic turnover, but also provided excellent stability to the Ni0.90Pd0.10 nanoparticle catalyst towards air and water and thus significantly enhanced its recyclability (up to 10 catalytic runs). The experiments revealed that the catalytic oxidation of 5‐HMF proceeded by the initial oxidation of the formyl group to carboxylic acid, and, subsequently, the conversion of alcohol to carboxylic acid via the formyl group to form FDCA. Moreover, the one‐pot direct transformation of fructose to furan carboxylic acid products (such as FDCA) was also achieved by using the Ni0.90Pd0.10 nanoparticle catalyst.

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

“…[198] Recently,w ee xplored oxidation of biomass-derived furans (furfural and HMF) over bimetallic Ni 1Àx Pd x (0.10 x 1) using air as an oxidizing agent. [200] We demonstrated that by tuningt he Ni to Pd contentsi nt he bimetallic Ni 1Àx Pd x catalyst, catalytic efficacy of Ni 1Àx Pd x catalysts towards the oxidation of furans can be controlled. It was observed that by decreasingt he Pd content in the bimetallic Ni 1Àx Pd x catalyst higher catalytic activity can be achieved,a nd hence,N i 0.90 Pd 0.10 exhibited the highest catalytic activity among all the studied catalysts.…”

“…Furthermore, Pd nanoparticles supported on Mg‐Al‐CO 3 hydrotalcite (Pd/HT) are also explored for an efficient catalytic oxidation of HMF to FDCA in water in the absence of any base additive . Recently, we explored oxidation of biomass‐derived furans (furfural and HMF) over bimetallic Ni 1− x Pd x (0.10≤ x ≤1) using air as an oxidizing agent . We demonstrated that by tuning the Ni to Pd contents in the bimetallic Ni 1− x Pd x catalyst, catalytic efficacy of Ni 1− x Pd x catalysts towards the oxidation of furans can be controlled.…”

Ruthenium‐Catalyzed C‐H Bond Activation/Arylation Accelerated by Biomass‐Derived Ligands

“…Synthesis of furan‐2‐carboxylic acid (2‐furoic acid) (L7) . The biomass derived furan derivative, furan‐2‐carboxylic acid (2‐furoic acid) was prepared by following the reported procedure using Ni 0.90 Pd 0.10 nanoparticles as a catalyst . A two‐neck round‐bottom flask was charged with freshly prepared 5 mol‐% Ni 0.90 Pd 0.10 nanoparticles followed by the addition of furan 2‐carboxyaldehyde (1 mmol, 82.8 µL).…”

Catalytic Transformation of Cellulose and Its Derivatives into Functionalized Organic Acids

“…The overall FDCA yield reached 53 %. Recently, a two‐step process for the conversion of fructose into FDCA was reported . In the first step, fructose was treated with 0.5 equivalents of NH 4 Cl in 2‐propanol at 353 K for 12 h. Then, water and 1.5 equivalents of Na 2 CO 3 were added to the mixture for further reaction at 353 K, with air bubbling through the solution in the presence of a Ni−Pd nanoparticle catalyst.…”