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The kinetics and mechanisms of selective maltose hydrogenation over Raney Ni remain poorly understood, which hinders the industrial advancement of maltitol production for biorefining. Herein, the impact of hydrogenation conditions and in‐depth mechanistic characterizations were carefully investigated in this research. Optimization of reaction conditions illustrated that maltitol formation was favored by moderate reaction temperatures (≤130°C), high hydrogen pressures (>7 MPa), and near‐neutral sodium phosphate buffer (pH = 6.47). Kinetic studies demonstrated the Ea of 45.5 kJ/mol for the hydrogenation of maltose. The in situ IR revealed that the hydrogenation of maltose over Raney Ni occurs in the order of ring opening and adsorption via CO of the aldose form followed by hydrogenation. The UV–vis spectra demonstrated the near‐neutral setting (pH = 6.47) promoted the production of open‐chain aldose conformation and selective CO hydrogenation to the corresponding alcohols. The present study on concentrated‐maltose hydrogenation paves the way for the industrial development of maltitol manufacturing. [ABSTRACT FROM AUTHOR]

A novel one-pot approach selects a hydrothermally synthesized Cu/SiO2 catalyst (consisting of Cu2O·SiO2 and Cu0 surface species) to catalyze the reduction of a series of fatty esters, fatty acids, and coconut oil to fatty alcohols at 240 °C in methanol without extraneous hydrogen, attaining around 85% conversion and 100% selectivity. [ABSTRACT FROM AUTHOR]

Correction for 'The conversion of a high concentration of lignin to cyclic alkanes by introducing Pt/HAP into a Ni/ASA catalyst' by Shufang Qin et al., Green Chem., 2020, 22, 2901–2908, DOI: 10.1039/D0GC00243G. [ABSTRACT FROM AUTHOR]

[Display omitted] • The multi-functional synergistic catalysis constructed an excellent and selective deoxygenation catalyst which could decarboxylate diverse fatty acids to alkanes under hydrogen-free conditions. • The Pt/HAP-IE has a much lower activation energy (127 kJ∙mol−1) and a fast rate (300 g∙g Pt −1∙h) for decarboxylation. • The unique adsorption mode activated carboxylates, which trended to be fast cleaved by the adjacent Pt nanoparticles anchored by OH groups to catalyze the target decarboxylation reaction. A highly effective and stable Pt/HAP catalyst was developed for the hydrogen-free deoxygenation of lipids to alkanes via specific stabilization and synergistic effect, which achieved ca. 90% yield at 320 °C at a high rate of 300 g∙g Pt −1∙h−1 with 50 wt% reactant concentration in dodecane. Such catalytic system was adapted to various triglyceride feedstock and even unprocessed waste oil, showing superior activities than other reported Pt catalysts. The Pt precursor was ion-exchanged with the OH surface groups of HAP, as confirmed by characterizations of CO 2 -TPD, NH 3 -TPD and IR, forming uniform and small Pt nanoparticles with an average size of 0.7 nm after reduction. Even after eight recycling runs, the particle sizes were slightly turned into 1.6 nm with high reactivity and stability. In situ IR spectra showed that carboxylic acid was physically adsorbed on Pt/SiO 2 and adsorbed as a bidentate on Pt/Al 2 O 3 , while adsorbed as a chelation on Pt/HAP-IE in comparison. Upon adsorption, protons of the carboxyl group were dissociated by phosphate, and the generated carboxylate anions were adsorbed on Ca2+ to form a chelated structure. Such adsorption mode activated carboxylates, which trended to be fast cleaved by the adjacent Pt nanoparticles anchored by OH groups to catalyze the target decarboxylation reaction, achieving the multi-functional synergistic catalysis. This Pt/HAP-IE catalyst can be applied to the hydrogen-free decarboxylation reactions, especially for the deoxygenation of compounds containing unsaturated C C, C O, C O, and O H bonds that are sensitive to hydrogen. [ABSTRACT FROM AUTHOR]

[Display omitted] • The non-noble metal catalyst CoNx/NC prepared by facile decomposition of ZIF-67. • CoNx/NC shows high yield 41.3 % of heptadecene for deoxygenation of stearic acid. • The heptadecene was generated via steric acid decarbonylation pathway. • The CoNx/NC catalyst can be easily recycled by magnetic separation. The development of highly efficient, low-cost supported catalysts is crucial for directly deoxygenating biomass fatty acids to long-chain olefins. However, additive-free olefin production, by dehydrative decarbonylation from fatty acids, is scarcely conducted owing to competing decarboxylation reactions. Herein, a green and cost-effective strategy is presented to improve the Co-catalyzed dehydrative decarbonylation of stearic acid, which produces a mixture of heptadecenes with yields of up to 41.3 % and a paraffin yield of 14.7 %. Experimental data, along with a detailed catalyst characterization, revealed that the surface CoN x species acted as the dominant active sites. Furthermore, the specific catalytic performance can be attributed to the dense defect sites, abundant vacancies, and mesoporous structures of the N-doped Carbon (NC) support. The as-prepared CoN x /NC catalysts were recovered and reused up to three times without significant deactivation. Additionally, we propose a possible reaction mechanism for fatty acid deoxygenation. This research makes a significant contribution toward advancing the performance of noble-metal-free deoxygenation catalysts for the production of unsaturated compounds in biomass conversions. [ABSTRACT FROM AUTHOR]