Construction Of Zirconium/Cobalt Catalysts And Their Catalytic Properties For Hydrogenation Of Biomass Derivatives

As a green renewable energy,the rational use of biomass can decrease the over-consumption of fossil energy in economic development.Biomass based platform chemicals,such as ethyl levulinic acid（EL）,furfural（FF）,5-hydroxymethylfurfural（HMF）,can be converted into valerolactone（GVL）,furfuryl alcohol（FA）,2,5-furandimethyl alcohol（BHMF）through hydrogenation.GVL,FA and BHMF are widely used as plasticizers,fuels and bio-based polymer monomers in the chemical industry.Compared with direct hydrogenation using H₂,the catalytic transfer hydrogenation（CTH）reaction with alcohol as hydrogen donor is characterized by mild conditions and high safety.At present,the catalytic materials for hydrogenation of aldehyde group catalyzed by CTH reaction still have the problems of high preparation cost or low reaction efficiency.The development of CTH materials with simple synthesis process,low cost and high selectivity has important application prospects.In this paper,adenosine monophosphate（AMP）,a natural organic compound with low price and many kinds of metal coordination functional groups,was used as the organic ligand and the zirconium monophosphate coordination polymer material,Zr-AMP,was synthesized in pure water.In the prepared Zr-AMP material,the phosphoric acid group and the nitrogen in the purine ring of AMP form a unique coordination structure by coordinating with Zr.Zr⁴⁺provides Lewis acid sites in Zr-AMP catalytic materials,while O^2-and N^3-coordinated with Zr provide Lewis basic sites.Uncoordinated phosphoric acid provides Br?nsted acid sites.The multifunctional sites in Zr-AMP catalytic materials can effectively promote the conversion of EL to GVL.When Zr-AMP was used for EL hydrogenation,the EL conversion rate reached 99.7%and GVL selectivity reached 99.5%at 160℃for 6h.Zr-AMP has good stability,and the yield of GVL decreased by only 4.1%after five cycles.CoZnOHF nanorods（CoZnF）were synthesized under mild conditions.Fluorine-doped cobalt-zinc solid solution nanowires,CoZnO&CoZnF,were prepared by calcining CoZnF in air at 330℃.In CoZnO&CoZnF,Co²⁺-O^2-/Zn²⁺-O^2-is the Lewis acid-base pair contained in the material,which can be used as the active sites for the CTH reaction of FF and HMF.Due to the high electronegativity of fluorine in CoZnF,which weakens the chemical bond between M-O,CoZnO&CoZnF is rich in oxygen vacancies.The presence of oxygen vacancy strengthens the interaction between Lewis acid site and carbonyl in reactants and reduces the hydrogenation barrier during the reaction.CoZnO&CoZnF can catalyze carbonyl hydrogenation efficiently due to its rich oxygen vacancies and unique one-dimensional structure.When CoZnO&CoZnF catalyzed the hydrogenation of HMF and FF,the yields of BHMF and FA were 96%and 98.1%,respectively,and the selectivity of aldehyde hydrogenation products was greater than 99%.