Phosphorus-Induced Activation of Ruthenium for Boosting Hydrogen Oxidation and Evolution Electrocatalysis

Abstract

Developing efficient electrocatalysts toward alkaline hydrogen oxidation and evolution reactions (HOR/HER) and fundamental understanding their catalytic mechanisms are highly desirable with the rapid development of hydrogen economy. Here, we report that the surface electronic structure of ruthenium (Ru) can be effectively modulated through phosphorus (P) doping to produce significantly enhanced catalytic HOR and HER performance in alkaline electrolyte. By controlling the amount of P, the resulted P–Ru/C exhibits outstanding catalytic activity, achieving a normalized exchange current density of 0.72 mA cm–2 and mass activity of 0.43 mA μg–1, approximately 5 and 3.5 times higher than those of Ru/C, respectively, and even 2 times higher than that of Pt/C (commercial 20 wt %) for HOR. Moreover, sixfold enhancement compared with Ru/C in the HER can be achieved from P–Ru/C. Experimental and density functional theory results indicate that electronic manipulation through P-doping is beneficial to the prominent HOR/HER performance and enhanced kinetics.

Three-Phase Heterojunction NiMo-Based Nano-Needle for Water Splitting at Industrial Alkaline Condition

“…Then, the three-phase heterojunction interface synergy effect and HER activity are studied via DFT computations. Particularly, the Δ G H* and electron distribution for the active atoms are investigated by DFT and density of states (DOS) [ 35 ]. Hence, we consider all possible active sites of Ni/MoO 2 @CN for HER and calculate their Δ G H* (Figs.…”

Engineering Ruthenium-Based Electrocatalysts for Effective Hydrogen Evolution Reaction

“…The H desorption behavior of Ru is weaker than that of Pt [14,34,35], thus regulating the desorption capacity of H on Ru is proven to be effective for improving the HER efficiency of Ru-based catalysts. Luo et al [31] developed P-doped Ru supported on XC-72 carbon (P-Ru/C) as a highly efficient 1 3…”

“…The high electronegativity of Ru (Pauling scale = 2.2) leads to a strong adsorption capacity for protons, resulting in the unfavorable desorption of H on the Ru surface, and it is known that Ru exhibits a more negative ΔGH* compared to Pt from the volcano plot [ 24 ]. Therefore, the electronegativity of Ru can be reduced by introducing heteroatoms that take away the electrons from Ru nucleus, increasing the desorption ability of Ru to hydrogen, thus enhancing the reaction rate of Heyrovsky or Tafel step [ 31 , 32 ]. It is worth noting that the heteroatom only plays a regulatory role and does not act as the active site, while Ru is still regarded as the active center of HER.…”

“…The H desorption behavior of Ru is weaker than that of Pt [ 14 , 34 , 35 ], thus regulating the desorption capacity of H on Ru is proven to be effective for improving the HER efficiency of Ru-based catalysts. Luo et al [ 31 ] developed P-doped Ru supported on XC-72 carbon (P-Ru/C) as a highly efficient HER electrocatalyst in alkaline media. P-Ru nanoparticles (NPs) were synthesized via colloidal synthesis, and the P content was controlled by different pyrolysis temperatures and times.…”

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Fig. 2 Effect of different doping strategies on free energy of reaction intermediates: a ΔG H* on Ru, P1-Ru, P2-Ru, and P3-Ru [ 31 ], with permission from the American Chemical Society. b Initial, intermediate, and final transition state free energy of Ru NCs/BNC and Pt/C in HER [ 33 ], with permission from the Elsevier Ltd. c Free energy of each reaction stage of RuMo alloying [ 47 ], with permission from the Wiley–VCH Verlag GmbH & Co. KGaA, Weinheim.

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