Electrocatalytic Oxidation Of Benzyl Alcohol By CoFe-Layered Double Hydroxides And Its Phosphide

Under the background of low carbon and energy transition,electrochemical organic oxidation using benzyl alcohol electrocatalytic oxidation reaction instead of slow oxygen evolution reaction has the advantages of low potential requirements,gas mixing inhibition,value-added products and so on,which is a promising research hotspot at present.This strategy can not only reduce the potential and energy consumption required by water electrolysis process,but also realize value-added product production.In this thesis,aiming at the problems of poor selectivity,expensive price and toxicity of traditional catalysts,Co-Fe layered double hydroxides nanosheets and Co-Fe bimetallic phosphating were prepared by one-step coprecipitate method and phosphating method respectively,and their effects on the electrocatalytic oxidation of benzyl alcohol were studied.The main research contents are as follows:(1)Co-Fe layered double hydroxides nanosheets(Co_xFe_y-LDHs)with different molar ratios of Co and Fe were successfully synthesized by one-step coprecipitate method for selective electrocatalytic oxidation of benzyl alcohol at the anode.By changing the Co/Fe molar ratio of Co_xFe_y-LDHs,the energy band structure of Co_xFe_y-LDHs and its adsorption of hydroxyl species were regulated,which significantly improved the reaction kinetics and enhanced the overall electrocatalytic activity to achieve the efficient conversion of benzyl alcohol and high selectivity of products.When the initial potential was 0.8 V vs.Ag/Ag Cl,the conversion of benzyl alcohol was96.79%and the selectivity of benzoic acid was 94.93%.(2)Based on the combination of Co and Fe,the d band center of the material could be regulated.Co Fe-LDHs was used as the precursor to obtain Co Fe P-m through phosphating and used as the anodic electrode.The regulating effect of phosphorus doping on electronic structure was studied by changing phosphating temperature.The introduction of phosphorus led to the weakening of the interaction force between metal atoms,the contraction of d band and the reduction of adsorption energy,thus enhancing the overall electrocatalytic activity.At the same time,the doping of polymetallic phosphide with metal ions and the synergistic action between them can effectively improve the chemical stability and charge transfer rate of the catalytic material,which is conducive to the full exposure of the catalytic active site and further promote the contact transmission of electrolytes.When the initial potential was 0.7 V vs.Ag/Ag Cl,the conversion of benzyl alcohol and the selectivity of benzoic acid were 97.71%and97.84%,respectively.