Mn-Doped RuO₂ Nanocrystals as Highly Active Electrocatalysts for Enhanced Oxygen Evolution in Acidic Media

Abstract

Currently, RuO 2 is a benchmark acidic oxygen evolution reaction (OER) catalyst. Nevertheless, its wide applications are always restricted by slow dynamics and limited durability. This paper reports a type of Mn-doped RuO 2 nanocrystals for boosting the OER catalytic performance in acidic media. The catalyst (named Mn-RuO 2 ) is prepared through annealing of Ru-exchanged Mn-based derivative at 300 °C. Such Mn-RuO 2 exhibits excellent acidic OER activity, with an overpotential of 158 mV at 10 mA cm −2 and a stability of 5000 cycles in the presence of sulfuric acid (0.5 mol/L). Both structural characterization and theoretical analysis show that the Mn doping in RuO 2 can tune the d-band center of Ru active sites and lower antibonding surface-adsorbate states, which leads to a decreased free energy of the rate-determining step, ultimately enhancing the intrinsic activity of RuO 2 .

Influence of the MnO2 Phase on Oxygen Evolution Reaction Performance for Low‐Loading Iridium Electrocatalysts

“…al [12b] loaded Co onto MnO 2 support to obtain a cost‐effective OER catalyst, which had low transfer resistance and high current density. Some researchers have also investigated the electrocatalytic performance of Mn oxides in acidic media [1a,6,12c, 15] . To decrease the overpotential and reduce the usage of noble metal, the ruthenium or iridium dioxide combined with manganese dioxide were developed [1a,15b] .…”

“…Some researchers have also investigated the electrocatalytic performance of Mn oxides in acidic media [1a,6,12c, 15] . To decrease the overpotential and reduce the usage of noble metal, the ruthenium or iridium dioxide combined with manganese dioxide were developed [1a,15b] . δ‐MnO 2 , with high surface area, abundant defects (vacancies) and adjustable electrical resistivity because of the cations (Na + ) intercalation, [16] was considered as the best support material because of the generated lattice distortion of IrO 2 and higher iridium state on it, which is beneficial for OER performance [15b,17] .…”

Rare-earth-regulated Ru-O interaction within the pyrochlore ruthenate for electrocatalytic oxygen evolution in acidic media

“…As shown in Fig. 2c, the as-prepared Nd 2 Ru 2 O 7 exhibited the highest ECSA-normalized intrinsic activity for OER in acid among ruthenium-based and iridium-based catalysts reported recently [33][34][35][36][37][38][39]. To better understand the kinetics of the RE 2 Ru 2 O 7 , the Tafel plots were measured (Fig.…”

“…The optimal OER catalysts ought to have neither too strong nor too weak metal-oxygen binding strengths [17,30]. It is generally accepted that the metal-oxygen binding strength could be regulated by modulating the d band center of the active sites [35,50]. Thus, the correlation between the Ru 4d band center and the intrinsic activity of RE 2 Ru 2 O 7 and RuO 2 was plotted in Fig.…”

Artificial Metalloprotein Nanoanalogues: In Situ Catalytic Production of Oxygen to Enhance Photoimmunotherapeutic Inhibition of Primary and Abscopal Tumor Growth

“…Moreover, the literature has already reported that the rutile structure of RuO 2 has an appropriate affinity for O 2 . [ 28 ] The RuO 2 NPs in RuO 2 @OVA NA were proved to be rutile‐structured (Figure S1A, Supporting Information), and thus, appropriate affinity for O 2 , endowed by its rutile structure, was presumed to promote 1 O 2 generation on the surface of RuO 2 NPs. In addition to exhibiting notable enzyme‐like and photodynamic properties, RuO 2 @OVA NAs also have the potential to achieve NIR‐mediated photothermal effects due to their excellent NIR absorption.…”