Enze Li

Bio: Enze Li is an academic researcher from Shanxi University. The author has contributed to research in topics: Water splitting & Electrolysis of water. The author has an hindex of 1, co-authored 1 publications receiving 4 citations.

Transition metal-based catalysts for electrochemical water splitting at high current density: current status and perspectives

Abstract: As a clean energy carrier, hydrogen has priority in decarbonization to build sustainable and carbon-neutral economies due to its high energy density and no pollutant emission upon combustion. Electrochemical water splitting driven by renewable electricity to produce green hydrogen with high-purity has been considered to be a promising technology. Unfortunately, the reaction of water electrolysis always requires a large excess potential, let alone the large-scale application (e.g., >500 mA cm−2 needs a cell voltage range of 1.8–2.4 V). Thus, developing cost-effective and robust transition metal electrocatalysts working at high current density is imperative and urgent for industrial electrocatalytic water splitting. In this review, the strategies and requirements for the design of self-supported electrocatalysts are summarized and discussed. Subsequently, the fundamental mechanisms of water electrolysis (OER or HER) are analyzed, and the required important evaluation parameters, relevant testing conditions and potential conversion in exploring electrocatalysts working at high current density are also introduced. Specifically, recent progress in the engineering of self-supported transition metal-based electrocatalysts for either HER or OER, as well as overall water splitting (OWS), including oxides, hydroxides, phosphides, sulfides, nitrides and alloys applied in the alkaline electrolyte at large current density condition is highlighted in detail, focusing on current advances in the nanostructure design, controllable fabrication and mechanistic understanding for enhancing the electrocatalytic performance. Finally, remaining challenges and outlooks for constructing self-supported transition metal electrocatalysts working at large current density are proposed. It is expected to give guidance and inspiration to rationally design and prepare these electrocatalysts for practical applications, and thus further promote the practical production of hydrogen via electrochemical water splitting.

Electrochemical Water Splitting: Bridging the Gaps between Fundamental Research and Industrial Applications

Abstract: Electrochemical water splitting represents one of the most promising technologies to produce green hydrogen, which can help to realize the goal of achieving carbon neutrality. While substantial efforts on a laboratory scale have been made for understanding fundamental catalysis and developing high-performance electrocatalysts for the two half-reactions involved in water electrocatalysis, much less attention has been paid to doing relevant research on a larger scale. For example, few such researches have been done on an industrial scale. Herein, we review the very recent endeavors to bridge the gaps between fundamental research and industrial applications for water electrolysis. We begin by introducing the fundamentals of electrochemical water splitting and then present comparisons of testing protocol, figure of merit, catalyst of interest, and manufacturing cost for laboratory and industry-based water-electrolysis research. Special attention is paid to tracking the surface reconstruction process and identifying real catalytic species under different testing conditions, which highlight the significant distinctions of corresponding electrochemical reconstruction mechanisms. Advances in catalyst designs for industry-relevant water electrolysis are also summarized, which reveal the progress of moving the practical applications forward and accelerating synergies between material science and engineering. Perspectives and challenges of electrocatalyst design strategies are proposed finally to further bridge the gaps between lab-scale research and large-scale electrocatalysis applications.

Large‐Scale Synthesis of Spinel NixMn3‐xO4 Solid Solution Immobilized with Iridium Single Atoms for Efficient Alkaline Seawater Electrolysis

Abstract: Seawater electrolysis not only affords a promising approach to produce clean hydrogen fuel but also alleviates the bottleneck of freshwater feeds. Here, a novel strategy for large‐scale preparing spinel NixMn3‐xO4 solid solution immobilized with iridium single‐atoms (Ir‐SAs) is developed by the sol–gel method. Benefitting from the surface‐exposed Ir‐SAs, Ir1/Ni1.6Mn1.4O4 reveals boosted oxygen evolution reaction (OER) performance, achieving overpotentials of 330 and 350 mV at current densities of 100 and 200 mA cm–2 in alkaline seawater. Moreover, only a cell voltage of 1.50 V is required to reach 500 mA cm–2 with assembled Ir1/Ni1.6Mn1.4O4‖Pt/C electrode pair under the industrial operating condition. The experimental characterizations and theoretical calculations highlight the effect of Ir‐SAs on improving the intrinsic OER activity and facilitating surface charge transfer kinetics, and evidence the energetically stabilized *OOH and the destabilized chloride ion adsorption in Ir1/Ni1.6Mn1.4O4. This work demonstrates an effective method to produce efficient alkaline seawater electrocatalyst massively.

Hierarchical Metal Sulfides Heterostructure as Superior Bifunctional Electrode for Overall Water Splitting.

Abstract: The development of high-active bifun ctional electrocatalyst for overall water splitting is of significant importance, but huge challenges remain. The key element depends on engineering the electronic structure and surface properties of material to achieve improved catalytic activity. Herein, we design a hierarchical nanowire array of metal sulfides heterostructure on nickel foam (FeCoNiS x /NF) as a novel type of hybrid electrocatalyst for overall water splitting. The hybrid structure endows plenty of catalytic active sites, strong electronic interactions, and high interfacial charge transferability, leading to superior bifunctional performance. As a result, the FeCoNiS x /NF catalyst delivers the low overpotentials of 97 mV and 260 mV at the current density of 50 mA cm -2 for HER/OER, respectively. Moreover, the FeCoNiS x /NF-based water electrolyzer exhibits a small potential of 1.57 V for a high current density of 50 mA cm -2 . These results indicate the promising application potential of FeCoNiS x /NF electrode for hydrogen generation. This work provides a new approach to develop robust hybrid materials as the highly active electrode for electrocatalytic water splitting.