Application Of Binary Alloy/porous Carbon Based On Metal Coordination Polymer In Electrocatalytic Hydrogen Evolution

Precious metal alloys are a kind of excellent electrocatalytic materials,such as platinum（Pt）metal used in electrocatalytic storage and conversion such as hydrolysis tanks and hydrogen fuel cells.However,in the process of electrooxidation and electroreduction in acid solution,the surface atoms of noble metals are easier to be removed,resulting in poor durability.Compared with the traditional single metal,the noble metal-based multi-element alloy doped with transition metal has superior physical and chemical properties,such as excellent hardness,oxidation resistance,corrosion resistance and wear resistance.At present,the most widely used and representative electrocatalysts are precious metals（such as Pt,Pd,Ru,Rh,Ir,Ag and Au）alloys or their alloys with transition metals（such as Fe,Co,Ni and Cu）,and are used in electrochemical reactions related to energy storage and conversion,including hydrogen evolution reaction（HER）,CO₂reduction reaction（CO₂RR）and N₂reduction reaction（NRR）,as well as oxygen-related reactions,It includes oxygen evolution reaction（OER）and oxygen reduction reaction（ORR）.The cluster size effect,electronic interaction and synergistic effect between noble metal atoms and other alloy metal atoms can improve the electrocatalytic activity.The excellent electrocatalytic performance is related to the coordination environment of the surface/interface atoms of the electrocatalyst and the adsorption energy of the reaction intermediates.Therefore,it is of great significance to explore different precursor alloy systems for electrocatalysis.Metal coordination polymer is a polymer composed of metal selective coordination unit and high conductivity backbone.It has adjustable porosity,large specific surface area and excellent metal position.The alloy formed after annealing can effectively adjust the electronic distribution of the metal site activity and greatly improve the electrocatalytic performance by virtue of the bimetallic coupling effect and the synergistic effect of multi-metals.In this paper,binary alloy/porous carbon materials were prepared by using a new metal coordination polymer as the precursor,and their performance under the condition of electrocatalytic hydrogen evolution was studied.The main research contents are as follows:1.Based on the application of noble metal Pt alloy materials in acid electrochemical hydrogen evolution,the metal cobalt porphyrin organic framework and Pt-based small molecules polymerized and calcined to form alloy materials:the cobalt metal porphyrin as the organic framework and Pt-based small molecules coordinated and polymerized to form alloy precursor,calcined in nitrogen to explore the performance of binary alloy Pt_xCo-T materials in electrochemical hydrogen evolution at different temperatures and different metal ratios.This platinum-cobalt binary alloy/porous carbon material provides a broad prospect for the application of efficient electrocatalytic hydrogen evolution.Among them,Pt₂Co-800 shows excellent over-potential under acidic conditions Theη₁₀value is 17 m V,which is significantly lower than Pt/C（63.4 m V）,Tafel slope(24 m V dec^-1)and ultra-long cycle stability.2.Based on the application of the noble metal Ru alloy material to the alkaline electrochemical hydrogen evolution,the ruthenium-based coordination polymer is constructed by the reaction of the noble metal ruthenium salt molecule with the tripolypyridine as the organic framework,and the anions in the ruthenium polymer are replaced by molybdenum ions,and the ruthenium-molybdenum binary alloy/porous carbon（Ru Mo-T）is formed after calcination as the alloy precursor.This kind of composite material has the synergistic effect of bimetallic and has good electrocatalytic activity in the alkaline hydrogen evolution reaction.Among them,Ru Mo-900 shows excellent overvoltage under alkaline conditions Theη₁₀value is97.2 m V,which is significantly lower than commercial Pt/C（187.9 mV）.