Lattice and Surface Engineering of Ruthenium Nanostructures for Enhanced Hydrogen Oxidation Catalysis

Abstract

Ru has recently been considered as a promising alternative of Pt toward hydrogen oxidation reaction (HOR) due to its lower price and similar hydrogen binding energy (HBE) in comparison to Pt. Nevertheless, the catalytic performance of Ru toward HOR is far from the satisfaction of practical application. Herein, it is demonstrated that the modification of Ru multi‐layered nanosheet (MLNS) with Ni can significantly promote the HOR performance. In particular, the HOR performance is strongly related to the Ni location on the surface or in the lattice of Ru MLNS. Experimental and theoretical investigations suggest that Ni in the lattice of Ru MLNS (lattice engineering) optimizes the HBE, while Ni species on the surface (surface engineering) decrease the free energy of water formation, as a result of the significantly enhanced HOR performance. The optimal catalyst, where Ni is located both on the surface and in the lattice, displays superior alkaline HOR performance to commercial Pt/C and Ru/C. The present study not only systematically reveals the significance of Ni modification on Ru toward HOR, but also promotes the fundamental researches on catalyst design for fuel cell reactions and beyond.

Surface/Interface Engineering of Hierarchical MoO2/MoNi4@Ru/RuO2 Heterogeneous Nanosheet Arrays for Alkaline Water Electrolysis with Fast Kinetics

“…The formation of MoNi 4 nanosheet arrays coated on the surface of MoO 2 cuboid arrays improves the surface oxophilicity that can promote water adsorption and activation, boosting the higher nonacidic hydrogen kinetics. [ 43‐46 ] This was further evidenced by the XPS signal peaks of O 1s (Figure 2f), in which the peaks at 531.3, 533, and 530.1 eV are deconvoluted to adsorbed H 2 O, adsorbed OH (OH ads ), and M—O, respectively. [ 22 ] When compared with MoO 2 /MoNi 4 cuboid nanosheet arrays (Figure S10d), hierarchical MoO 2 /MoNi 4 @Ru/ RuO 2 heterogeneous nanosheet arrays possessed a greater amount of M—O bond, suggesting its enhanced adsorption of H 2 O and OH ads that improves the electrolysis of water.…”

RuSe2–CoTe Heterogeneous Surfaces Coated with NC Layer for Excellent HER Performance under Alkaline Condition

“…Hydrogen is a high energy density carrier that can effectively alleviate human dependence on fossil energy and facilitate the realization of carbon neutrality. − In recent years, electrocatalytic hydrogen evolution reaction (HER) has been a promising high-purity hydrogen production technology, attracting a large number of researchers’ research interest. , Until now, the platinum-based electrocatalysts show high activity for electrocatalytic HER, while their widespread use has been severely hampered by the scarcity of resources and high prices , Thus, it is essential to synthesize Pt-free HER catalysts with excellent HER performance in alkaline solutions. , …”

“…5,6 Until now, the platinum-based electrocatalysts show high activity for electrocatalytic HER, while their widespread use has been severely hampered by the scarcity of resources and high prices 7,8 Thus, it is essential to synthesize Pt-free HER catalysts with excellent HER performance in alkaline solutions. 9,10 The optimized d-band electronic structure makes Ru has a hydrogen binding capacity similar to Pt (∼65 kcal mol −1 ), but its price is far lower than Pt, 11,12 and it is chemically inert to aggressive electrolytes, making it a promising alternative to Pt. 13 In particular, the modulation of metal Ru by nonmetallic anions can promote the desorption of H to a certain extent.…”

Regulation of Rate‐Determining Step on (RhxNi1‐x)2P for Enhanced Alkaline Hydrogen Oxidation Reaction

“…[26] On this basis, enhancing the OHBE of catalysts though introducing oxyphilic sites has been considered as an efficient approach to promote their catalytic activities toward alkaline HOR. [27][28][29][30] Unfortunately, the exact role of OHBE for alkaline HOR is still elusive. Moreover, regulating the RDS of alkaline HOR through enhancing the OHBE of electrocatalysts to accelerate the reaction kinetics, has been rarely reported.…”

“…demonstrated that the moderately enhanced OHBE can lower the energy barrier of the water dissociation step, which has been often considered as the rate‐determining step (RDS), and thereby accelerate the alkaline HER kinetics, through changing the RDS of alkaline HER from water dissociation step to OH ad desorption step [26] . On this basis, enhancing the OHBE of catalysts though introducing oxyphilic sites has been considered as an efficient approach to promote their catalytic activities toward alkaline HOR [27–30] . Unfortunately, the exact role of OHBE for alkaline HOR is still elusive.…”