The Preparation Of MOFs Derivative Electrocatalyst And Its Oxygen Reduction Performance

Efficient catalyst materials are key to improving new energy conversion equipment.Precious metals such as platinum?Pt?have high catalytic performance,but their high cost and poor stability hinder practical applications.Therefore,it is particularly important to find a suitable catalyst material.Metal-organic frameworks?MOFs?are porous functional materials formed by the interactions of metal-node ions and organic ligands through coordination bonds.The synthesis method is simple and the structure is controllable,which has widely application in gas storage,photoluminescence,drug loading and catalysis.However,the conductivity of MOFs is poor.In this work,MOFs were used as the precursors.After high-temperature carbonization and acid treatment,the derivatives of MOFs have good conductivity and can apply for electrocatalysis.The specific research contents are as follows:Here,we use amine-functionalized Al-MOFs?NH₂-MIL-53?Al??as a nitrogen source and carbon's precursor to provide a simple synthesis of nitrogen-doped porous carbon?NPC-MILs?for oxygen reduction reaction.NPC-MIL has good ORR catalytic potential as a non-metallic catalyst.The optimized NPC-MIL-900?carbonized at 900??exhibits a ORR catalytic activity to comparable with commercial Pt/C.In addition,the chrono-current measurement shows that the stability of NPC-MIL-900 catalyst is better than Pt/C.The chronoamperometry also indicates that the NPC-MIL-900 catalyst is more resistant to methanol in alkaline electrolytes than Pt/C.These indicate that NPC-MIL-900 has potential applications in fuel cells.Based on the preparation of ZIF-67?Zeolitic imidazolate framework-67?by solution method,bimetallic MOFs?ZIF-67?NiCo??were synthesized by in situ replacement of metallic nickel.Then ZIF-67?NiCo?were directly carbonized to obtain derivatives of MOFs and the electrochemical properties of derivatives were explored.By controlling the doping ratio of the materials and the carbonization temperature,it can be found the non-precious metal electrocatalysts have the best ORR catalytic activity.In addition,the ZIF-67?NiCo-40%?-C-800 catalyst has better stability and higher methanol tolerance in an alkaline system.This work provides a simple and scalable approach for the preparation of tunable metal proportion doped porous non-precious metal carbon materials,and has broad application prospects.At the same time,it provides a design idea for the next step to design a more efficient catalyst material.