An efficient and pH-universal ruthenium-based catalyst for the hydrogen evolution reaction

• Published in: Nature nanotechnology Vol. 12; no. 5; pp. 441 - 446
• Main Authors: Mahmood, Javeed, Li, Feng, Jung, Sun-Min, Okyay, Mahmut Sait, Ahmad, Ishfaq, Kim, Seok-Jin, Park, Noejung, Jeong, Hu Young, Baek, Jong-Beom
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.05.2017; Nature Publishing Group
• Subjects: 639/301/299/886; 639/638/161/886; 639/925/357/1018; Bonding strength; Carbon; Catalysts; Electrochemistry; Electrons; Energy efficiency; Fourier transforms; Hydrogen; Hydrogen evolution; letter; Materials Science; Media; Morphology; Nanoparticles; Nanotechnology; Nanotechnology and Microengineering; Platinum; Ruthenium; Spectrum analysis; Stability; Transmission electron microscopy; South Korea
• ISSN: 1748-3387; 1748-3395; 1748-3395
• DOI: 10.1038/nnano.2016.304

Ruthenium nanoparticles homogeneously dispersed in a nitrogenated, two-dimensional carbon matrix show high turnover frequency and small overpotential for hydrogen evolution reaction both in acidic and alkaline media. The hydrogen evolution reaction (HER) is a crucial step in electrochemical water splitting and demands an efficient, durable and cheap catalyst if it is to succeed in real applications 1 , 2 , 3 . For an energy-efficient HER, a catalyst must be able to trigger proton reduction with minimal overpotential 4 and have fast kinetics 5 , 6 , 7 , 8 , 9 . The most efficient catalysts in acidic media are platinum-based, as the strength of the Pt–H bond 10 is associated with the fastest reaction rate for the HER 11 , 12 . The use of platinum, however, raises issues linked to cost and stability in non-acidic media. Recently, non-precious-metal-based catalysts have been reported, but these are susceptible to acid corrosion and are typically much inferior to Pt-based catalysts, exhibiting higher overpotentials and lower stability 13 , 14 , 15 . As a cheaper alternative to platinum, ruthenium possesses a similar bond strength with hydrogen (∼65 kcal mol –1 ) 16 , but has never been studied as a viable alternative for a HER catalyst. Here, we report a Ru-based catalyst for the HER that can operate both in acidic and alkaline media. Our catalyst is made of Ru nanoparticles dispersed within a nitrogenated holey two-dimensional carbon structure (Ru@C 2 N). The Ru@C 2 N electrocatalyst exhibits high turnover frequencies at 25 mV (0.67 H 2  s −1 in 0.5 M H 2 SO 4 solution; 0.75 H 2  s −1 in 1.0 M KOH solution) and small overpotentials at 10 mA cm –2 (13.5 mV in 0.5 M H 2 SO 4 solution; 17.0 mV in 1.0 M KOH solution) as well as superior stability in both acidic and alkaline media. These performances are comparable to, or even better than, the Pt/C catalyst for the HER.