Unlocking the Potential of 5‑Hydroxy-2(5H)-furanone as a Platform for Bio-Based Four Carbon Chemicals

Industrial chemicals with a four-carbon structure, including maleic acid, 1,4-butanediol, γ-butyrolactone, and pyrrolidones, are derived from petroleum. Catalytic synthesis of these C4 chemicals from biomass is challenging because of the scarcity of C4 sugars in biomass feedstock. We show that 5-hydroxy-2(5H)-furanone (5H5F), produced by catalytic oxidation of biomass-derived furfural, is a versatile platform for several oxygen- and nitrogen-containing C4 chemicals. In our study, 5H5F was synthesized in 92% yield by room-temperature oxidation of furfural using TS-1 catalyst. As a platform chemical, 5H5F’s mild reactivity, attributed to the electrophilic carbon attached to the hydroxyl group, enabled its oxidation, reduction, and reductive aminolysis using carbon-supported noble metal catalysts. Industrial C4 chemicals like maleic acid (93%), γ-butyrolactone (93%), 1,4-butanediol (60%), tetrahydrofuran (64%), and 2-pyrrolidone (67%) were obtained from 5H5F under mild conditions (100–150 °C). We envision that 5H5F will be adopted as a platform for C4 chemicals owing to its ease of synthesis and selective transformation to multiple chemicals using heterogeneous catalysts

Cellulose Hydrolysis Using Oxidized Carbon Catalyst in a Plug-Flow Slurry Process

The catalytic conversion of cellulose to glucose at the industrial scale is a sustainable approach to the production of fuels and chemicals. Herein, we report the hydrolysis of cellulose to glucose using an inexpensive carbon catalyst in a continuous slurry process. A carbon catalyst prepared by air oxidation showed the highest activity for cellulose hydrolysis owing to the large number of weakly acidic functional groups. The air-oxidized carbon catalyst hydrolyzed cellulose in a plug-flow slurry reactor after mix-milling to produce soluble β-1,4-glucans. Further hydrolysis of the β-1,4-glucans to glucose was achieved using a fixed-bed reactor containing Amberlyst-70 catalyst in series with the slurry reactor to obtain glucose in 59% yield. Another approach was to use dilute H₃PO₄ for the hydrolysis of the β-1,4-glucans to glucose with a 70% yield, resulting in a space time yield of glucose of 456 kg m^–3 h^–1. The simple design, short residence time, and high space time yield will enable the scaleup of this process using existing chemical technology

Stepwise Pore Size Reduction of Ordered Nanoporous Silica Materials at Angstrom Precision

A facile vacuum-assisted vapor deposition process has been developed to control the pore size of ordered mesoporous silica materials in a stepwise manner with angstrom precision, providing an unprecedented paradigm for screening a designer hydrophobic drug nanocarrier with optimized pore diameter to maximize drug solubility