title: An efficient and pH-universal ruthenium-based catalyst for the hydrogen evolution reaction.
abstract: 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. For an energy-efficient HER, a catalyst must be able to trigger proton reduction with minimal overpotential and have fast kinetics. The most efficient catalysts in acidic media are platinum-based, as the strength of the Pt-H bond is associated with the fastest reaction rate for the HER. 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. As a cheaper alternative to platinum, ruthenium possesses a similar bond strength with hydrogen (∼65 kcal mol-1), 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@C2N). The Ru@C2N electrocatalyst exhibits high turnover frequencies at 25 mV (0.67 H2s-1in 0.5 M H2SO4solution; 0.75 H2s-1in 1.0 M KOH solution) and small overpotentials at 10 mA cm-2(13.5 mV in 0.5 M H2SO4solution; 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.
authors.affiliation: School of Energy and Chemical Engineering, Centre for Dimension-Controllable Organic Frameworks, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST, Ulsan 44919, South Korea.
authors.forename: Javeed
authors.identifier: 0000-0002-9159-3336
authors.initials: J
authors.lastname: Mahmood
authors.affiliation: School of Energy and Chemical Engineering, Centre for Dimension-Controllable Organic Frameworks, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST, Ulsan 44919, South Korea.
authors.forename: Feng
authors.initials: F
authors.lastname: Li
authors.affiliation: School of Energy and Chemical Engineering, Centre for Dimension-Controllable Organic Frameworks, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST, Ulsan 44919, South Korea.
authors.forename: Sun-Min
authors.identifier: 0000-0002-8196-1748
authors.initials: SM
authors.lastname: Jung
authors.affiliation: School of Natural Science, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST, Ulsan 44919, South Korea.
authors.forename: Mahmut Sait
authors.initials: MS
authors.lastname: Okyay
authors.affiliation: School of Energy and Chemical Engineering, Centre for Dimension-Controllable Organic Frameworks, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST, Ulsan 44919, South Korea.
authors.forename: Ishfaq
authors.initials: I
authors.lastname: Ahmad
authors.affiliation: School of Energy and Chemical Engineering, Centre for Dimension-Controllable Organic Frameworks, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST, Ulsan 44919, South Korea.
authors.forename: Seok-Jin
authors.initials: SJ
authors.lastname: Kim
authors.affiliation: School of Natural Science, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST, Ulsan 44919, South Korea.
authors.forename: Noejung
authors.initials: N
authors.lastname: Park
authors.affiliation: UNIST Central Research Facilities, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST, Ulsan 44919, South Korea.
authors.forename: Hu Young
authors.initials: HY
authors.lastname: Jeong
authors.affiliation: School of Energy and Chemical Engineering, Centre for Dimension-Controllable Organic Frameworks, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST, Ulsan 44919, South Korea.
authors.forename: Jong-Beom
authors.initials: JB
authors.lastname: Baek