Reductive catalytic fractionation of flax shives by using nickel formate for in situ catalyst generation and the shives as a support for the metal : научное издание
Библиографическое описание:Reductive catalytic fractionation of flax shives by using nickel formate for in situ catalyst generation and the shives as a support for the metal : научное издание / Valentin V. Sychev [et al.]. - Текст : непосредственный // Biomass Conversion and Biorefinery. - 2025. - Т.15, №10. - P. 15417-15426. - This research was supported by the Russian Science Foundation, grant No 20-63-47109 (2020-2023), and conducted within the framework of the budget project FWES-2021-0017 (2024) for the Institute of Chemistry and Chemical Technology SB RAS. - ISSN 2190-6815. - ISSN 2190-6823, DOI 10.1007/s13399-024-06365-9.
Аннотация:Nanoscale nickel particles formed in situ using nickel formate as a precursor are proposed for the reductive catalytic fractionation (RCF) of flax shives. The examination of solid products of flax shives RCF by XRD revealed that characteristic reflections for Ni0 (111), (200), (220) at 2θ angles of 44, 52, and 76, respectively, are present in the X-ray diffraction patterns, hinting at the metal in situ reduction. The presence of Ni oxides was also confirmed via XPS (signals 855.8 and 874.3 eV, Ni0/Niox = 0.0). The alternative Ni-catalyst was pre-deposited on flax shives via reduction of nickel formate by hydrazine. The pre-deposited Ni particles were found to be XRD amorphous hinting at fine distribution and XPS confirmed both metallic and oxidized states Ni0, Ni2+, Ni3+ at the surface (Ni0/Niox = 0.14). Monomeric compounds, such as 4-propylguaiacol, 4-propenylguaiacol, and 4-propanolguaiacol, were obtained with a total yield of 6.92 wt.% in the presence of in situ formed Ni. Excluding the molecular hydrogen from the reactor drops the lignin monomers yield from 6.92 to 3.80 wt.%, but the latter value exceeds the yield of the monomers of non-catalytic hydrogenation with H2 by a factor of 3 (1.44 wt.%). Ni particles catalyze the process of lignin hydrogenation by formate ion; decreasing the Ni content in the reaction mass while keeping formate ion concentration at the same level drops the monomers yield down to the level corresponding to the non-catalytic hydrogenation with using molecular H2. The process over nickel pre-deposited via reduction by hydrazine provided a higher total phenolic monomers yield of up to 9.12 wt.% equaled to the yields in the presence of the known Ni/C catalysts. The selectivity on the main product among phenolic monomers – 4-propanolguaiacol reached 42%.
