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Schematic illustration of HDO of phenol to benzene in the biphasic catalytic process.

The shift in consumer preference toward ecofriendly plastic products is driving the overall bioplastics and biopolymers market. As such, there is a strong demand for innovative processes that produce monomers from biomass feedstocks as an alternative to fossil resources. For instance, amino acids with two amino groups (e.g., L-lysine) are a unique biomass material that can be refined to produce diamines, which are further used to synthesize biobased nylons. Herein, we demonstrate that the diamine (cadaverine) was produced in a high yield from the second most-produced commercial amino acid (L-lysine). In the selective deoxygenation of lysine, the synergistic effect of the carbon-supported ruthenium catalyst and the phosphoric acid cocatalysts, the role of hydrogen gas, and the activation and suppression of the functional groups of lysine were elucidated in great detail. Under the optimum conditions, a 100% conversion of L-lysine and an ∼94% total yield of amines, with an ∼51% selectivity to diamines, were attained at 200 °C within 2 h. Moreover, both characterization and kinetic studies of the probe reactions were used to understand the reaction mechanism. The knowledge gained in this study may provide fundamental insights into the selective deoxygenation of other N-containing renewable feedstocks.

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Conversion of fatty acids to diesel-range hydrocarbons suffers from elevated reaction temperature or low selectivity in single liquid-phase processes. Herein the biphasic interfacial catalytic process was developed for the decarboxylation of fatty acids to produce alkane hydrocarbons using Pd/C catalyst at the water-organic solvent interface. An exceptionally high carbon yield of 91.7 ± 2.3% (theoretical maximum 94.4%) and a high selectivity of ∼99% to n-heptadecane were obtained from the conversion of stearic acid in the cycloalkane/water biphasic solvent system at a relatively low temperature (260 °C). The kinetic study of the conversion of stearic acid and oleic acid in the biphasic catalytic process was investigated and the activation barriers of both reactions were determined and compared to those of the monophasic catalytic processes. Both the experimental studies and MD simulations were performed to elucidate the synergistic effects of water and various organic solvents, which stabilize the carboxylate group and the hydrophobic hydrocarbon tail in a fatty acid molecule, respectively, and improve the kinetic rates and the selectivity. The application of the biphasic tandem catalytic process (biTCP) approach was further extended to the decarboxylation of a wide selection of saturated and unsaturated fatty acids, triglycerides (e.g., glyceryl trioleate), and oilseed biocrude oil (e.g., canola oil) to produce high-quality diesel fuels.

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Chitin, a long-chain polymer of N-acetyl-D-glucosamine (NAG) and the most abundant natural nitrogen-containing organic material in the world, is far under-utilized than other biomass resources. Herein, we demonstrate a highly efficient deoxygenation process to convert chitin monomer, i.e., NAG, into various amines, which are the ubiquitous platform chemicals in chemical industry. In the presence of H 2 and Ru/C catalyst, the oxygen atoms in the glucosamine molecules are removed in the form of H 2 O and/or CO/CO 2 , whereas CO is hydrogenated to CH 4 . By optimizing the reaction conditions, $50% yield of various amines was obtained via the selective deoxygenation of NAG. The reaction mechanism has been proposed. These findings not only promote shell biorefinery in green chemistry and fishery industry but also provide chemicals for material science, resulting in expanding cooperation in new areas such as clean energy, energy conservation, environment protection, and infrastructure.