Electrocatalytic activity of layered MAX phases for the hydrogen evolution reaction

The hydrogen evolution reaction (HER) is important for the advancement of next-generation electrochemical energy devices. The search for an alternative inexpensive catalyst for energy conversion to replace expensive and rare noble metals is of high priority. There has been a significant push to investigate electrocatalysis of various layered materials for hydrogen evolution. However, the electrocatalytic activity of layered MAX phases remains largely unexplored. Herein, electrocatalytic activity studies of MAX (Ti₂AlC, Ta₂AlC, Ti₂SnC, Ti₃SiC₂, V₂AlC, Mo₂TiAlC₂, and Cr₂AlC) phases are conducted. Material and electrochemical characterization are carried out to understand the morphology and catalytic activity, respectively. From Tafel slope analysis, it was found that proton adsorption is the rate-limiting step for all the MAX phases studied. Double transition-metal MAX carbides (Mo₂TiAlC₂) showed better catalytic activity for HER than single transition-metal MAX carbides.