Catalytic Activity of Coatings of FeCrNiWMoCoCB Metallic Glasses on a Metal Substrate

Abstract

A study is made of the catalytic activity of coatings based on FeCrNiWMoCoCB metallic glasses (MGs) on a substrate of 35 steel intended for the decomposition of a methylene blue solution. Five coatings of different composition with predominantly amorphous structure are synthesized via the precipitation of MG coating via electrosparking in an environment of granules of crystalline alloys. The roughness of coatings according to Ra is 9 to 14 µm, which considerably increases the area of interaction between MGs and the methylene blue solution. Unlike tungsten and molybdenum, the presence of nickel and cobalt in the composition of the metallic glass promotes the catalytic activity of coatings. Coatings based on the Fe₃₃Cr₈Ni₈W₈Mo₈Co₈C₁₆B₁₁ composition show the best catalytic properties; the energy of activation of the self-decomposition of the methylene blue solution in the presence of hydrogen peroxide falls by 800%. It is shown that the efficiency of this catalytic system can be almost tripled by etching it in HNO₃ (30%) for 380 s, due to an increase in the porosity and specific surface area of the coating. The proposed approach can substantially reduce the cost of producing the catalytic elements of reactors via the one-stage deposition of coatings of MGs on metallic materials.