Electrocatalytic activity of hypo-hyper d-electrocatalysts (Me/TiO2/MWCNTs) based on Co-Ru in alkaline hydrogen electrolyser

Abstract

This study is concerned with preparation and characterization of Co-Ru based hypo-hyper d-electrocatalysts aimed for water electrolysis. The composition of the studied electrocatalysts was: 10 % mixed metallic phase (Co : Ru = 1 : 1 wt., Co:Ru = 4 : 1 wt. and Co : Ru : Pt = 4 : 0.5 : 0.5), 18 % TiO2 as a crystalline anatase deposited on activated multiwalled carbon nanotubes (MWCNTs). For comparison, corresponding electrocatalysts with pure hyper d-metallic phase (Co and Ru) were prepared. The structural characterization of the studied electrocatalysts was performed by means of XRD, SEM and FTIR analysis. The prepared hypo-hyper d-electrocatalysts were electrochemically studied by cyclic voltammetry and potentiodynamic method in the alkaline hydrogen electrolyser. The order of the catalytic activity for hydrogen evolution of studied electrocatalysts was the following: Ru > CoRuPt (4 : 0.5 : 0.5, wt.) > CoRu (1 : 1 wt.) > CoRu (4 : 1 wt.) > Co. The electrocatalyst with only 20 % precious metals (Pt and Ru) in the metallic phase (the rest being Co-metal) exhibited excellent performance approaching that of the electrocatalyst with 100 % precious metallic phase (Ru).