Identifying the Activation Mechanism and Boosting Electrocatalytic Activity of Layered Perovskite Ruthenate

Abstract

SrRuO3 as a rare conductive perovskite ruthenate has attracted increasing attention for application in energy conversion. Here, the electrocatalytic activity for the hydrogen evolution reaction (HER) of thermally synthesized layered SrRuO3 is investigated and shows a considerable activation during cathodic polarization in alkaline solution. The analysis demonstrates the electrode activation is caused by the increased hydrophilicity of SrRuO3 surface, revealing the influence of the surface properties on HER performance. For further improving the catalytic activity of perovskite ruthenate, the RuO2/SrRuO3 (RSRO) heterostructure is fabricated in situ by reducing the thermal decomposition temperature of 1000 °C for SrRuO3 to 600 °C. The appropriate lattice parameter of SrRuO3 ensures a good lattice match, which results in a strong interaction between SrRuO3 and RuO2. Hence, the RSRO substantially outperforms the corresponding single‐component oxides. In addition, the increased active sites induced by the rapid improvement of hydrophilicity of RSRO surface further highlight its structural advantage for catalytic hydrogen generation. The experimental and theoretical computation results consistently validate the positive synergistic effect among SrRuO3 and RuO2 in tuning the atomic and electronic configuration.

Rational Construction of Ruthenium‐Cobalt Oxides Heterostructure in ZIFs‐Derived Double‐Shelled Hollow Polyhedrons for Efficient Hydrogen Evolution Reaction

“…[4,42] For the C 1s spectrum of RCO/Co 3 O 4 -350 DSHPs in Figure S17A (Supporting Information), three peaks are allocated to CO (288.5 eV), CO (286.6 eV), and CC/ CC (284.8 eV), and the peak at 282.0 eV is corresponding to the Ru 3d 5/2 of Ru 4+ . [19,41] The O 1s spectrum (Figure S17B, Supporting Information) is fitted to four oxygen contributions and the following peaks at 529.5 and 530.0 eV can be attributed to Ru-O and Co-O bands, [19,43] respectively. Furthermore, the peak at 531.1 eV is usually associated with O-vacancy, O-H and chemisorbed oxygen (O ad ), [8,10] and the peak at 532.5 eV is corresponding to the physicochemical absorbed H 2 O at the surface of catalysts.…”

“…Among the various hybrid HER electrocatalysts with heterojunction, Ru oxide is rarely discussed, and only few reports show that the heterojunction based on Ru oxide possesses superior HER activity. [8,19] Moreover, compared with simple nanoparticle or bulk structures, the proper construction of special nano-structures, especially the hollow structure, is also conducive to improve the catalytic activity of electrocatalyst. [20,21] To be specific, hollow structure with high surface area supplies sufficient active sites for surface-related reactions, such as surface redox reaction and adsorption/desorption.…”

“…The electronic interplay between Co and Ru species produces the electronegativity difference in RCO/ Co 3 O 4 -350 DSHPs, which facilitates the separation of H and OH − intermediates, thereby accelerating the decomposition of H 2 O molecules [4,42]. For the C 1s spectrum of RCO/Co 3 O 4 -350 DSHPs in FigureS17A(Supporting Information), three peaks are allocated to CO (288.5 eV), CO (286.6 eV), and CC/ CC (284.8 eV), and the peak at 282.0 eV is corresponding to the Ru 3d 5/2 of Ru 4+ [19,41]. The O 1s spectrum (FigureS17B, Supporting Information) is fitted to four oxygen contributions and the following peaks at 529.5 and 530.0 eV can be attributed to Ru-O and Co-O bands,[19,43] respectively.…”

Neutral-Alkaline Hybrid Water Electrolysis at Less Than 1.43 V Enabled by a Branched NiCo-Hydroxysulfide Nanoarray

“…A new peak occurred at ∼529.3 eV in the O 1s spectrum after OER, which belongs to the lattice oxygen (Figure S14f). , These data indicate that an amorphous CoOOH layer might be formed on the surface of NiCo-CHS during the OER test.…”

Recent Advances in Perovskite Catalysts for Efficient Overall Water Splitting

“…Despite considerable efforts, the OER/HER electrocatalytic performances of most perovskite oxides are still inferior to those of commercial IrO 2 /RuO 2 or Pt/C catalysts. Recent studies have shown that doping a small number of precious metals (i.e., Pt, Ru, and Ir) in perovskites can significantly improve their activity and stability [61,[112][113][114][115]. For instance, Wang et al prepared a series of LaCo 1-x Pt x O 3-δ (× = 0, 0.02, 0.04, 0.06, and 0.08) perovskite oxides.…”