Electron-deficient titanium single-atom electrocatalyst for stable and efficient hydrogen production

• Published in: Nano energy 2020-12, Vol.78, p.105151, Article 105151
• Main Authors: Jang, Injoon, Im, Kyungmin, Shin, Hyeyoung, Lee, Kug-Seung, Kim, Hyungjun, Kim, Jinsoo, Yoo, Sung Jong
• Format: Article
• Language: English
• Subjects: High-valent titanium; Hydrogen evolution reaction; Molybdenum phosphide; Single atom catalyst
• ISSN: 2211-2855
• DOI: 10.1016/j.nanoen.2020.105151

To further improve the hydrogen-based energy system, there is an urgent need to replace precious metal-based hydrogen evolution reaction catalysts, including Pt-based materials, with nonprecious metal catalysts for electrochemical production of hydrogen from water. In this work, we propose a novel titanium-doped molybdenum phosphide (Ti–MoP) catalyst. Ti–MoP exhibits a low overpotential of 81.5 mV at 10 mA·cm−2. In particular, the remarkable improvement in material stability and electrochemical durability allows the catalyst to maintain its initial activity after prolonged exposure to air and shows accelerated electrochemical durability testing under acidic conditions. The experimental results and theoretical calculations revealed that the high durability is the result of electronically reduced Mo and P caused by Ti, and the high activity is a result of the optimization of the free energy of hydrogen adsorption (ΔGH) of the abnormally high-valence Ti. [Display omitted] •Reliable method for synthesizing transition metal phosphide nanoparticles.•High activity and durability for hydrogen evolution reaction of TiSA/MoP catalyst.•Electron rearrangement of Ti, Mo and P due to new structure of TiSA/MoP.•High HER activity of Ti which is extremely electron-deficient.•High stability of extremely electron-rich Mo and P.