Preparation Of Fe/Co/Ni Based Catalysts And Their Catalytic Performance For The Electrooxidation Of H₂O₂

Electrode material is the key component of fuel cells.The preparation of anode materials with excellent performance is very important to improve the performance of fuel cells.Non-precious metals are of great significance to the commercial application of fuel cells.In this thesis,relatively inexpensive iron,cobalt,and nickel are used as the metal source,sodium hypophosphite is the non-metal source,and carbon cloth is the matrix of electrode.The composite catalytic electrode is prepared by the constant current electrodeposition method,and the structure and catalytic performance of different the composite catalytic electrodes are studyed by XRD,SEM,EDS,etc.Characterization methods are supplemented by CV,EIS,CA and other electrochemical test methods.Firstly,by using a simple electrodeposition method on the pre-treated carbon cloth,Fe-P,Co-P alloy electrodes are electrodeposited in one step（according to the concentration of the phosphorus source in the deposition solution,the electrodes are named Fe-P（0.1,0.2,0.3）,Co-P（0.1,0.2,0.3,0.4））.The electrochemical performance test showed that all the catalysts supported by the electrodes have a certain catalytic performance for H₂O₂.Among the Fe-P electrodes,the Fe-P（0.2）electrode has the best performance,and among the Co-P electrodes,the Co-P（0.2）electrode has the best performance.The optimal electrolyte for Fe-P（0.2）electrode is 3.0 mol/L Na OH+2.0 mol/L H₂O₂,and the optimal electrolyte for Co-P（0.2）electrode is 2.0 mol/L Na OH+2.0 mol/L H₂O₂.At 0.5 V vs.Ag/Ag Cl potential,the current density of Fe-P（0.2）electrode in the optimal electrolyte concentration can reach 314.67 m A/cm²,and the current density of Co-P（0.2）electrode can reach 356.20 m A/cm².During the 1250 s test time,the current density of Fe-P（0.2）electrode is maintained at 61.77 m A/cm² and the current density of Co-P（0.2）electrode is maintained at 113.92 m A/cm² at 0.15 V vs.Ag/Ag Cl potential.The electrochemically active area of Fe-P（0.2）electrode is 18.33 cm²,while the electrochemically active area of Co-P（0.2）electrode is 110.83 cm².Through investigation and comparison,it is found that the catalytic performance of Co-P（0.2）electrode for H₂O₂ electrooxidation is significantly better than that of Fe-P（0.2）electrode.Secondly,based on the above-mentioned optimal Co-P（0.2）electrode,keeping the optimal phosphorus source concentration in the electrodeposition solution unchanged,and adding Ni²⁺without changing the concentration of metal ions in the solution.Changing the value of[Ni²⁺]:[Co²⁺]and exploring the optimal electrodeposition conditions to prepare Ni-Co-P catalytic electrodes.The electrode with the best catalytic performance is Ni-Co-P（2-1）electrode.In 1.0 mol/L H₂O₂+2.0 mol/L Na OH electrolyte,at 0.5 V vs.Ag/Ag Cl potential,the oxidation current density of Ni-Co-P（2-1）electrode is as high as408.51 m A/cm².At 0.5 V vs.Ag/Ag Cl potential,the current density within 1250 s test time is stable above 86.85 m A/cm².The electrochemically active area of Ni-Co-P（2-1）electrode is the largest among Ni-Co-P electrodes,which is 102.33 cm².The activation energy calculated according to the Arrhenius equation is 4.82 k J/mol.