A Comparison of Photodeposited RuO_x for Alkaline Water Electrolysis

Abstract

The storage of renewable energy is a pressing challenge to overcome in the transition toward a power grid based on plentiful, yet intermittent energy supplies. The renewables-driven electrolysis of water to form hydrogen fuel is an attractive avenue, but requires better oxygen-evolution reaction (OER) catalysts to be feasible at scale. RuO 2 is touted as one of the superior OER catalysts but only under acidic conditions; RuO 2 electrocatalysts suffer from poor stability under alkaline conditions. In this work, we evaluate three photodeposited RuO x OER electrocatalysts, all prepared via a scalable photodeposition method. Based on electrochemical and spectroscopic studies (X-ray photoelectron spectroscopy and X-ray absorption spectroscopy), our main findings are that nanocrystalline RuO x catalysts outperform their amorphous counterpart and are more stable under alkaline (0.1 M KOH) conditions. This works thus lifts a major hurdle toward the use of RuO x for alkaline water electrolysis.

Advances and insights in amorphous electrocatalyst towards water splitting

“…The noble metals Ir/Ru are used as benchmark catalysts in electrolytic water separation technology. However, the high voltage required for OER and the slow kinetics hinders new catalyst development [139][140][141][142]. The unique structure and various anisotropies of amorphous materials provide new directions in the search for stable and efficient catalysts [143][144][145][146].…”

Hybridization of MXene and covalent organic frameworks as electroactive materials for Li–S batteries and oxygen electrocatalysis

“…12 The forward-looking work carried out by Cai et al revealed that an imine covalent organic framework (TAPB-PDA-COF) was selected as a host material to accommodate active sulfur, and that the performance of Li-S batteries could be regulated by changing the type of conductive additive, which encouraged researchers to explore more appropriate conductive additives. 13 In terms of sustainable energy conversion technology, processes such as water electrolysis, 14 electrochemical synthesis of hydrogen peroxide, 15 and research on fuel cells 16 are regarded as having practical application potential. In water electrolysis, the oxygen evolution reaction (OER) at the anode possesses a decisive role in transforming H 2 O to O 2 by acquiring electrons from the reaction system.…”

“…In terms of sustainable energy conversion technology, processes such as water electrolysis, 14 electrochemical synthesis of hydrogen peroxide, 15 and research on fuel cells 16 are regarded as having practical application potential. In water electrolysis, the oxygen evolution reaction (OER) at the anode possesses a decisive role in transforming H 2 O to O 2 by acquiring electrons from the reaction system.…”