Carbonate-Catalyzed Room-Temperature Selective Reduction of Biomass-Derived 5-Hydroxymethylfurfural into 2,5-Bis(hydroxymethyl)furan

5-Hydroxymethylfurfural and its Downstream Chemicals: A Review of Catalytic Routes

Biomass assumes an increasingly vital role in the realm of renewable energy and sustainable development due to its abundant availability, renewability, and minimal environmental impact. Within this context, 5-hydroxymethylfurfural (HMF), derived from sugar dehydration, stands out as a critical bio-derived product. It serves as a pivotal multifunctional platform compound, integral in synthesizing various vital chemicals, including furan-based polymers, fine chemicals, and biofuels. The high reactivity of HMF, attributed to its highly active aldehyde, hydroxyl, and furan ring, underscores the challenge of selectively regulating its conversion to obtain the desired products. This review highlights the research progress on efficient catalytic systems for HMF synthesis, oxidation, reduction, and etherification. Additionally, it outlines the techno-economic analysis (TEA) and prospective research directions for the production of furan-based chemicals. Despite significant progress in catalysis research, and certain process routes demonstrating substantial economics, with key indicators surpassing petroleum-based products, a gap persists between fundamental research and large-scale industrialization. This is due to the lack of comprehensive engineering research on bio-based chemicals, making the commercialization process a distant goal. These findings provide valuable insights for further development of this field.

Metabolite profiling of Drynariae Rhizoma using 1H NMR and HPLC coupled with multivariate statistical analysis

Drynariae Rhizoma has been used to treat bone diseases and kidney deficiency in traditional medicine. Recently its aqueous extract was reported to enhance memory function. Although the Japanese standards for non-Pharmacopoeial crude drugs 2022 prescribed Drynaria roosii as the botanical origin, some counterfeits and both raw and stir-fired crude drugs are available in markets. To distinguish Drynariae Rhizoma derived from D. roosii appropriately from others and verify the validity of uses of stir-fried ones, 1H NMR-based metabolite profiling coupled with HPLC were performed. Raw samples derived from D. roosii contained naringin (1), neoeriocitrin (2), 5,7-dihydroxychromone-7-O-neohesperidoside (3), caffeic acid 4-O-β-D-glucoside (4), protocatechuic acid (5), trans-p-coumaric acid 4-O-β-D-glucoside (6), and kaempferol 3-O-α-L-rhamnoside 7-O-β-D-glucoside (8). Stir-fried samples were characterized by presence of 5-hydroxymethyl-2-furaldehyde (13), and were divided into two types; one possessing similar composition to raw samples (Type I) and another without above components except 5 (Type II). Quantitative analyses using qHNMR and HPLC, followed by principal component analysis demonstrated that the raw samples had higher contents of 1 (0.93-9.86 mg/g), 2 (0.74-7.59 mg/g), 3 (0.05-2.48 mg/g), 4 (0.27-2.51 mg/g), 6 (0.14-1.26 mg/g), and 8 (0.04-0.52 mg/g), and Type II had a higher content of 5 (0.84-1.32 mg/g). The counterfeit samples derived from Araiostegia divaricata var. formosana were characterized by higher content of ( -)-epicatechin 3-O-β-D-allopyranoside (10) (1.44-11.49 mg/g) without 1 and 2. These results suggested that Drynariae Rhizoma samples derived from other botanical origins and Type II stir-fried samples cannot substitute for D. roosii rhizome.

Recent advances in catalytic synthesis of 2,5-furandimethanol from 5-hydroxymethylfurfural and carbohydrates

5-Hydroxymethylfurfural (HMF) is a versatile platform chemical derived from the dehydration of renewable carbohydrates (typically glucose/fructose-based monosaccharides, oligosaccharides, and polysaccharides). Some useful compounds, such as 2,5-furandimethanol (FDM), 2,5-dimethylfuran (DMF) and 2,5-dimethyltetrahydrofuran (DMTHF), have been synthesized by reduction of HMF. Among these, FDM is a promising diol and can be further converted towards fine chemicals, liquid fuels and polymer materials. In this review, some typical catalytic systems for the synthesis of FDM from both HMF and carbohydrates were summarized. The discussion focused on controlling the reaction networks for the reduction of HMF. The reaction mechanisms and the stability of the catalysts were introduced briefly. Last but not least, the prospects of effective production of FDM were discussed as well.

Reduced metal nanocatalysts for selective electrochemical hydrogenation of biomass-derived 5-(hydroxymethyl)furfural to 2,5-bis(hydroxymethyl)furan in ambient conditions

Selective electrochemical hydrogenation (ECH) of biomass-derived unsaturated organic molecules has enormous potential for sustainable chemical production. However, an efficient catalyst is essential to perform an ECH reaction consisting of superior product selectivity and a higher conversion rate. Here, we examined the ECH performance of reduced metal nanostructures, i.e., reduced Ag (rAg) and reduced copper (rCu) prepared via electrochemical or thermal oxidation and electrochemical reduction process, respectively. Surface morphological analysis suggests the formation of nanocoral and entangled nanowire structure formation for rAg and rCu catalysts. rCu exhibits a slight enhancement in ECH reaction performance in comparison to the pristine Cu. However, the rAg exhibits more than two times higher ECH performance without compromising the selectivity for 5-(HydroxyMethyl) Furfural (HMF) to 2,5-bis(HydroxyMethyl)-Furan (BHMF) formation in comparison to the Ag film. Moreover, a similar ECH current density was recorded at a reduced working potential of 220 mV for rAg. This high performance of rAg is attributed to the formation of new catalytically active sites during the Ag oxidation and reduction processes. This study demonstrates that rAg can potentially be used for the ECH process with minimum energy consumption and a higher production rate.

Biomass-derived chemical substitutes for bisphenol A: recent advancements in catalytic synthesis

Bisphenol A is an oil-derived, large market volume chemical with a wide spectrum of applications in plastics, adhesives and thermal papers. However, bisphenol A is not considered safe due to its endocrine disrupting properties and reproductive toxicity. Several functional substitutes of bisphenol A have been proposed in the literature, produced from plant biomass. Unless otherwise specified, the present review covers the most significant contributions that appeared in the time span January 2015-August 2019, describing the sustainable catalytic synthesis of rigid diols from biomass derivatives. The focus is thereupon on heterogeneous catalysis, use of green solvents and mild conditions, cascade processes in one-pot, and continuous flow setups. More than 500 up-to-date references describe the various substitutes proposed and the catalytic methods for their manufacture, broken down according to the main biomass types from which they originate.

Catalytic Biomass to Renewable Biofuels and Biomaterials

As the only renewable carbon source, biomass can be converted into biofuels, chemicals, and biomaterials, such as ethanol, butanol, glucose, furfural, biochar, and bio-oils, and is considered as a substitute for fossil oil [...]

Heterogeneous Catalytic Upgrading of Biofuranic Aldehydes to Alcohols

Heterogeneous catalytic conversion of lignocellulosic components into valuable chemicals and biofuels is one of the promising ways for biomass valorization, which well meets green chemistry metrics, and can alleviate environmental and economic issues caused by the rapid depletion of fossil fuels. Among the identified biomass derivatives, furfural (FF) and 5-hydroxymethylfurfural (HMF) stand out as rich building blocks and can be directly produced from pentose and hexose sugars, respectively. In the past decades, much attention has been attracted to the selective hydrogenation of FF and 5-hydroxymethylfurfural using various heterogeneous catalysts. This review evaluates the recent progress of developing different heterogeneous catalytic materials, such as noble/non-noble metal particles, solid acids/bases, and alkali metal salts, for the efficient reduction of bio-based furanic aldehydes to alcohols. Emphasis is laid on the insights and challenges encountered in those biomass transformation processes, along with the focus on the understanding of reaction mechanisms to clarify the catalytic role of specific active species. Brief outlook is also made for further optimization of the catalytic systems and processes for the upgrading of biofuranic compounds.

Low-temperature catalytic hydrogenation of bio-based furfural and relevant aldehydes using cesium carbonate and hydrosiloxane

A benign catalytic system consisting of Cs₂CO₃ and PMHS can effectively reduce furfural to furfuryl alcohol with a high yield of 99.5% at 25–80 °C via siloxane, which is also applicable to other aromatic aldehydes.