Application Of Rhenium-based Metal Materials In Electrocatalytic Hydrogen Evolution Reaction

With the increasing demand for fossil energy since the Industrial Revolution,it has inevitably led to their rapid consumption,which has caused a serious energy crisis and global environmental pollution problems.Therefore,hydrogen energy quickly attracted the attention of scientists due to its high energy density and pollution-free.The electrocatalytic hydrogen evolution reaction（HER）is an efficient and environmental friendly approach to manufacture hydrogen gas.During electrocatalytic HER,strong acid solution（e.g.0.5 M H2SO4）or alkaline media（e.g.1 M KOH）is usually used as electrolyte to carry out HER owing to their high ionic conductivities in the laboratory.At the same time,considering the practical application of the water electrolysis cell,the ideal electrocatalyst needs to exhibit superior catalytic performance and durability in both strong acid and strong base electrolytes.Therefore,it is of great significance to study an electrocatalyst that can be efficient and stable in different media.Since rhenium（Re）metal exhibits high corrosion resistance in both acidic and alkaline electrolytes,this paper will be divided into three parts,using simple and direct solid-phase synthesis to prepare a series of rhenium-based intermetallic compounds.Later,we will apply the obtained samples to the electrolysis of water with different electrolytes to produce hydrogen,which opens up a new direction for the development of pH universal catalysts.In the first part,Ti5Re24,ZriRe24 and Hf5Re24 with cage structure were synthesized.Re metal is also included for comparison.The HER activity of these materials was tested.It can be seen that ZrsRe24 exhibits superior catalytic performance and good stability in strong acid（η10=91.6 mV）and strong base（η10=90.2 mV）electrolytes.Combining the results of electrochemical tests and theoretical calculations,it was surprisingly found that the HER activity of this series of compounds under acidic and alkaline conditions is almost the same,indicating that the OH molecule does not poison the active site,and even makes the material reach a slightly optimized position.In the second part,based on previous studies,a rhenium-based compound ZrRe2 belonging to the same space group as the previous one was synthesized.In addition.Ru atoms were added to the raw material to replace some Re atoms until the Re atoms were completely replaced to obtain ZrRu2,which improved the electrocatalytic activity of ZrRe2.After the test,it was found that Zr4Re7Ru can significantly improve the electrochemical performance of the raw material in strong acid and alkali media while maintaining excellent durability.In the third part,in order to satisfy high catalytic activity and reduce cost at the same time,we tried to dope the raw material with cheap transition metals（Fe,Co and Ni）to replace the precious metal Ru.And combined with the results of the previous part,we chosed a doping ratio of 4:1:7 and synthesized Zr4MRe7（M=Fe,Co and Ni）by arc melting.Among them,Zr4NiRe7 requires 103.2 mV and 69.2 mV overpotentials in 0.5 M H2SO4 and 1 M KOH solutions to reach current density of 10 mA/cm2 respectively,and even achieves the same effect as doping Ru in the raw material.It is believed that this paper can provide new ideas for the development of efficient and stable pH universal catalysts.