Electrocatalytic Oxygen Evolution Reaction (OER) on Ru, Ir, and Pt Catalysts: A Comparative Study of Nanoparticles and Bulk Materials

Abstract

A comparative investigation was performed to examine the intrinsic catalytic activity and durability of carbon supported Ru, Ir, and Pt nanoparticles and corresponding bulk materials for the electrocatalytic oxygen evolution reaction (OER). The electrochemical surface characteristics of nanoparticles and bulk materials were studied by surface-sensitive cyclic voltammetry. Although basically similar voltammetric features were observed for nanoparticles and bulk materials of each metal, some differences were uncovered highlighting the changes in oxidation chemistry. On the basis of the electrochemical results, we demonstrated that Ru nanoparticles show lower passivation potentials compared to bulk Ru material. Ir nanoparticles completely lost their voltammetric metallic features during the voltage cycling, in contrast to the corresponding bulk material. Finally, Pt nanoparticles show an increased oxophilic nature compared to bulk Pt. With regard to the OER performance, the most pronounced effects of nanoscaling were identified for Ru and Pt catalysts. In particular, the Ru nanoparticles suffered from strong corrosion at applied OER potentials and were therefore unable to sustain the OER. The Pt nanoparticles exhibited a lower OER activity from the beginning on and were completely deactivated during the applied OER stability protocol, in contrast to the corresponding bulk Pt catalyst. We highlight that the OER activity and durability were comparable for Ir nanoparticles and bulk materials. Thus, Ir nanoparticles provide a high potential as nanoscaled OER catalyst.

Benchmarking the Stability of Oxygen Evolution Reaction Catalysts: The Importance of Monitoring Mass Losses

“…Overview of the state of the art for the oxygen evolution reaction: a) In acid media. Data adapted from: Present work for sputtered RuO 2 , [16] for Ru, Ir and Pt polycrystalline (pc) and nanoparticles (NP), [17] for Ru 0.7 Ni 0.3 O 2Ày nanocrystals, [18] for RuCo and RuIr NP, [19] for IrO 2 film and [7] for RuO 2 and IrO 2 NP (# normalised to oxide area). b) In alkaline media.…”

“…RuO 2 is an extensively studied material with a high activity in acidic electrolyte. [16,[43][44][45] However, the stability of RuO 2 is limited at high overpotentials. MnO x has been proposed as a more abundant and inexpensive alternative to RuO 2 ; [46][47][48][49] not only is it active for the OER, but also for the ORR, opening up possibilities for its use in regenerative fuel cells.…”

A highly-efficient oxygen evolution electrode based on defective nickel-iron layered double hydroxide

“…However, the low efficiency and sluggish kinetics of oxygen evolution reaction (OER) catalysts have restricted the large-scale production of hydrogen [4,5]. Precious metal catalysts (such as IrO 2 and RuO 2 ) have to be involved in the electrode [6][7][8][9] to lower the overpotential and facilitate the OER process, but the limited performance (e.g., an onset potential of 1.5 V) has still hindered their commercialization [10][11][12][13]. Instead, 3d-transition metals (Ni, Co, Fe, etc.)…”

Functional links between stability and reactivity of strontium ruthenate single crystals during oxygen evolution

“…The selection of such cost-effective oxide materials, however, was pursued chiefly by testing the activity of high-surface area powders (in the micron size range) or thin polycrystalline films 24 . Two important advantages of using high-surface area oxide powders supported on a conductive support are that the conductivity issue can be overcome, as well as that the synthesis methods are well established [25][26][27][28] .…”