Catalytic Oxidation Of α-pinene And Dye Adsorption Based On Novel Nanosized Fe-MOFs

α-Pinene,a readily available biomass,can be used as a renewable raw material for manufacturing perfume and pharmaceutical intermediate.Thus it is important to develop a new recyclable catalyst system forα-pinene transformation.Nanoscale metal-organic frameworks（NMOFs）containing more metal-centered Lewis acidic active sites and active sites in organic ligands（such as-OH,-NH₂,etc.）can be used as a catalyst for oxidizingα-pinene.Ionic liquids（ILs）can be used as additives to regulate the microenvironment of NMOFs-based catalytic system,thereby significantly improving the catalytic performance of NMOFs.On the other hand,the use of dyes inevitably causes environmental pollution,hence it is particularly important to develop suitable methods for dye wastewater.MOF can remove organic dye molecules in water by electrostatic interaction,hydrophilic hydrophobic interaction,π-πstacking and hydrogen bonding.Therefore,the main contents of this paper are as follows:1.Rod-shaped nano Fe-PMA-n（n is hydrothermal reaction temperature）catalysts with different size,specific surface area and pore size were prepared at different temperatures（i.e.,60-200 ^oC）for catalytic oxidation ofα-pinene using TBHP.In the absence of solvent,5.0%mmol[C₄mim]Cys is facile to form a synergistic reaction system of Fe-PMA-60/[C₄mim]Cys.Under the optimal conditions,the conversion of substrate can reach 99.8%,and the total selectivity of the main products（verbenone and verbenol）was 81.0%.The repeated use of Fe-PMA-60 for 8 times showed no significant change in the catalytic results,demonstrating excellent reusability.The in-situ Fe-PMA-60/[C₄mim]Cys nanocomposite was confirmed by TEM,FT-IR,DRUV-vis and UV-vis characterizations.And the corresponding reaction mechanism was presented.2.Firstly,Fe-PMA-150 was synthesized by hydrothermal method,and then a series of composite catalyst Ag/Fe-PMA containing silver nanoparticles was obtained for the catalytic oxidation ofα-pinene with molecular oxygen after solution impregnation and Na BH₄ reduction.Oxidation ofα-pinene using Ag/Fe-PMA-1.5 as the catalyst,1 atm O₂ as oxygen source,n（α-pinene）:n（[C₄mim]Ala）:n（TBHP）=1:0.025:0.1,the conversion was 72.3%,and the total selectivity of the main products（α-pinene oxide,verbenone,and verbenol）was 92.9%.In the catalytic reaction,Ag NPs and Fe-PMA in the composite Ag/Fe-PMA synergistically improve the catalytic oxidation ofα-pinene,which can increase the conversion efficiency of Fe-PMA support by 1.3 times.The amino acid ionic liquid[C₄mim]Ala can increase the conversion rate of Ag/Fe-PMA-1.5 by 1.2 times,which implys a good synergistic effect and favors the selective oxidation ofα-pinene under mild conditions（1 atm O₂,60 ^oC）.The in-situ Fe-PMA-60/[C₄mim]Ala nanocomposite was confirmed by FT-IR,DRUV-vis and UV-vis characterization.3.Novel adsorbents,such as[C₄mim]Cl-Fe-tpta,were synthesized by hydrothermal reaction using imidazole ionic liquids of different chain length as the template and terphenyltetracarboxylic acid（H₄tpta）as a ligand,and then identified by FT-IR and TEM.The structure and morphology of[C₄mim]Cl-Fe-tpta were found to be grain-like NMOFs.The adsorbent such as[C₄mim]Cl-Fe-tpta removes methylene blue（MB）in aqueous solution byπ-πinteraction,hydrogen bonding and electrostatic interaction,and the adsorption amount of MB can reach 558mg g^-1,significantly better than the common MOFs material.Importantly,the imidazole ionic liquids with different chain length can regulate the dye adsorption performance of obtained NMOFs.