MOF-Derived High Entropy Alloy Electrocatalyst with Low Amount of Noble Metal for Alkaline HER

Although numerous researches for electrochemical hydrogen generation reactions have been conducted, they have the limitation of requiring the use of large amounts of several noble metal elements such as Pt, Ru, and Ir for hydrogen evolution electrocatalysts. In addition, there are increasing researches of high-entropy alloy electrocatalysts, which has many advantages for electrocatalysis like high stability, tunability of element composition and ratio, various active sites, etc., while their synthesis methods usually require harsh consition. In this research, we introduce CoNiCuMnRu/C high entropy alloy electrocatalyst for alkaline hydrogen evolution reaction, synthesized by using metal-organic frame work template as a precursor, followed by ion exchange method and pyrolysis. CoNiCuMnRu/C shows very low HER overpotential of only 19 mV at 10 mA cm -2 and high mass activity of 1.21 A mg Ru -1 at -0.07 V vs. RHE, succeeding commercial Ru/C and Pt/C. PDOS calculation shows Ni and Co sites act as active sites of water adsorption and ICOHP indicates insertion of low amount of Ru changes hydrogen adsorption feature of the high-entropy alloy electrocatalyst.