Metal‐Organic Framework‐Based Electrocatalysts for Acidic Water Splitting

Abstract

The proton exchange membrane water electrolysis system has long been considered a promising technique for the generation of hydrogen owing to its high electrolytic efficiency, reliability, and quick response to renewable energy sources. At present, noble metals and their oxides (e.g., Pt, IrO2, and RuO2) are widely used as high active electrocatalysts for accelerating the conversion efficiency of the water electrolysis process, especially in acidic media. Nevertheless, the scarcity and instability seriously impede their large‐scale application in practice. In the past years, metal‐organic frameworks (MOFs) have proven to be an ideal platform for designing efficient and cost‐effective electrodes due to their unique physicochemical properties. In this review, the fundamental catalytic mechanisms of hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in acidic media are discussed first. Then, design strategies and advanced characterizations for MOF‐based water‐splitting catalysts are summarized. Finally, the recent research advances of MOF‐based electrocatalysts for HER and OER in acidic electrolytes, along with current challenges and future opportunities, are provided.

Selective oxygen reduction reaction: mechanism understanding, catalyst design and practical application

“…Therefore, ORR electrochemical testing can be employed not only for the evaluation and screening of catalysts, but also for the investigation of catalytic mechanisms. 55 However, relying solely on a single testing method is not reliable, hence the importance of combining multiple measurement techniques to accurately evaluate catalyst properties, such as elemental composition, electrochemically active surface area (ECSA), Faraday efficiency (FE), and electrochemical stability, among others. Nevertheless, many of the current methods lack standardization, posing obstacles in accurate comparison of the catalytic activity and stability of various catalysts.…”

Unlocking the Na-Storage Behavior in Hard Carbon Anode by Mass Spectrometry

“…The schematic of the TMS and OEMS gas analysis systems is shown in Figure b. The OEMS characterization was employed to quantify the consumption and generation of multiple gases accurately during the electrochemical process of the HC-Na half-cell. − Using two titration agents (D 2 O and H 2 SO 4 ), the TMS characterization was employed on the HC electrodes discharged from its pristine state to various cutoff voltages, including 0.5, 0.2, 0.15, 0.1, 0.02, 0 V vs Na + /Na and with an additional Na-plating process about 20% discharge capacity excess (20% excess).…”

Single atom-decorated transition metal oxide nanomaterials for efficient oxygen evolution reaction

“…, Ru and Ir) are the most effective electrocatalysts for the OER, however, they have disadvantages of high cost and scarcity. 13,14 Generally, two approaches have been proposed to overcome the limitations: (1) minimizing the utilization of noble metals without losing performances and (2) exploring non-noble metal-based catalysts. 15 During electrocatalysis, the reactants can contact only with the near surface atoms, and the role of the inner atoms is negligible.…”