Preparation Of Porous Organic Frameworks For Biomass Derived Ketone Conversion

Porous materials can be divided into inorganic porous materials,inorganic-organic hybrid porous materials and organic porous materials according to their elemental composition and bonding modes.Organic porous materials have wide applications in ion exchange,gas storage,catalysis and so on because of their various skeleton structure,feasible modification,large surface area,and high stability.In this work,a series of organic porous materials were selected as scaffold to modify the catalytic centers,and their application in biomass conversion was studied.A series of porous organic framework(POF)samples with hexagonal structure(P6/m space group)and pore diameter in the range of 1.2-2.9 nm were synthesized by selecting different length of building blocks.A series of POF catalysts(Ru/POF-L0,Ru/POF-L1,Ru/POF-L2 and Ru/POF-L3)were obtained by introducing catalytic groups through post modification.The adsorption capacity of POF catalyst for acetophenone was determined by experimental investigation and density functional theory calculations.It was proved that there is a strong π-π interaction between POF skeletons and substrates,which restricts the free movement and rotation of substrates in the pore channels.The results show that the Ru/POF heterogeneous catalyst with pore diameter of 2.4 nm has the best catalytic performance in the hydrogenation of biomass-derived ketones to produce chiral alcohols.Amino acid residues in the cavity of enzyme limit the free movement and rotation of substrates,thus achieving high efficiency and high selectivity of the catalytic performance.To simulate this catalytic process,we intercalated a flexible polymer chain with different functional groups in the one-dimensional POF channel.Hydrogen bonding,π-π interaction and electrostatic effect are introduced to immobilize the spatial configuration of substrate molecules.The optimized POF catalyst has an efficient asymmetric catalytic performance in the hydrogenation of aromatic ketones,because the free movement and rotation of the aromatic ketone substrate are restricted.