Search

Electrolysis that reduces carbon dioxide (CO2) to useful chemicals can, in principle, contribute to a more sustainable and carbon-neutral future1–6. However, it remains challenging to develop this into a robust process because efficient conversion typically requires alkaline conditions in which CO2precipitates as carbonate, and this limits carbon utilization and the stability of the system7–12. Strategies such as physical washing, pulsed operation and the use of dipolar membranes can partially alleviate these problems but do not fully resolve them11,13–15. CO2electrolysis in acid electrolyte, where carbonate does not form, has therefore been explored as an ultimately more workable solution16–18. Herein we develop a proton-exchange membrane system that reduces CO2to formic acid at a catalyst that is derived from waste lead–acid batteries and in which a lattice carbon activation mechanism contributes. When coupling CO2reduction with hydrogen oxidation, formic acid is produced with over 93% Faradaic efficiency. The system is compatible with start-up/shut-down processes, achieves nearly 91% single-pass conversion efficiency for CO2at a current density of 600 mA cm−2and cell voltage of 2.2 V and is shown to operate continuously for more than 5,200 h. We expect that this exceptional performance, enabled by the use of a robust and efficient catalyst, stable three-phase interface and durable membrane, will help advance the development of carbon-neutral technologies.

Fuel cells have attracted extensive attention due to their high conversion efficiency and environmental friendliness. However, their wider application is limited by the poor activity and high cost of platinum (Pt), which is widely used as the cathode catalyst to overcome the slow kinetics associated with oxygen reduction reaction (ORR). Pt-based composites with one-dimensional (1D) nanoarchitectures demonstrate great advantages towards efficient ORR catalysis. This review focuses on the recent advancements in the design and synthesis of 1D Pt-based ORR catalysts. After introducing the fundamental ORR mechanism and the advanced 1D architectures, their synthesis strategies (template-based and template-free methods) are discoursed. Subsequently, their morphology and structure optimization are highlighted, followed by the superstructure assembly using 1D Pt-based blocks. Finally, the challenges and perspectives on the synthesis innovation, structure design, physical characterization, and theoretical investigations are proposed for 1D Pt-based ORR nanocatalysts. We anticipate this study will inspire more research endeavors on efficient ORR nanocatalysts in fuel cell application.

Electrosynthesis has emerged as an enticing solution for hydrogen peroxide (H2O2) production. However, efficient H2O2generation encounters challenges related to the robust gas–liquid–solid interface within electrochemical reactors. In this work, we introduce an effective hydrophobic coating modified by iron (Fe) sites to optimize the reaction microenvironment. This modification aims to mitigate radical corrosion through Fe(II)/Fe(III) redox chemistry, reinforcing the reaction microenvironment at the three-phase interface. Consequently, we achieved a remarkable yield of up to 336.1 mmol h–1with sustained catalyst operation for an extensive duration of 230 h at 200 mA cm–2without causing damage to the reaction interface. Additionally, the Faradaic efficiency of H2O2exceeded 90% across a broad range of test current densities. This surface redox chemistry approach for manipulating the reaction microenvironment not only advances long-term H2O2electrosynthesis but also holds promise for other gas-starvation electrochemical reactions.

Efficient and durable electrocatalysts are essential for achieving high electrocatalytic efficiency in electrocatalytic reactions, forming the bedrock of effective electrochemical energy technologies. Electrocatalysis is a complex process, marked by intricate reaction system and crucial interfacial interactions, leading to diverse degrees of reconstruction changes in electrocatalysts, affecting both catalytic capabilities and structural integrity. This review delves into the development and prospects of electrocatalyst reconstruction within the electrochemical energy conversion and storage technologies. It elucidates the underlying motivation and mechanism driving reconstruction in various oxidation/reduction reaction systems. Moreover, it elucidates the evolution and comprehension of highly effective electrocatalysts that emerge as a result of this reconstruction phenomenon. The characterizations of catalyst reconstruction are thoroughly examined through the cutting-edge imaging/spectroscopy technologies, enabling dynamic reconstruction tracking and identification. Finally, this work highlights the challenges and opportunities associated with advancing reconstructed electrocatalysts. The primary objectives are to fathom the intricacies of reconstruction and its structural evolution for precise catalyst design. Additionally, it aims to regulate the reconstruction process to enhance the electrocatalyst longevity, stabilize catalytic reactions, and ultimately facilitate the implementation of electrochemical technologies.

The electrochemical reduction reaction of carbon dioxide (CO2RR) into valuable products offers notable economic benefits and contributes to environmental sustainability. However, precisely controlling the reaction pathways and selectively converting key intermediates pose considerable challenges. In this study, our theoretical calculations reveal that the active sites with different states of copper atoms (1–3–5–7–9) play a pivotal role in the adsorption behavior of the *CHO critical intermediate. This behavior dictates the subsequent hydrogenation and coupling steps, ultimately influencing the formation of the desired products. Consequently, we designed two model electrocatalysts comprising Cu single atoms and particles supported on CeO2. This design enables controlled *CHO intermediate transformation through either hydrogenation with *H or coupling with *CO, leading to a highly selective CO2RR. Notably, our selective control strategy tunes the Faradaic efficiency from 61.1% for ethylene (C2H4) to 61.2% for methane (CH4). Additionally, the catalyst demonstrated a high current density and remarkable stability, exceeding 500 h of operation. This work not only provides efficient catalysts for selective CO2RR but also offers valuable insights into tailoring surface chemistry and designing catalysts for precise control over catalytic processes to achieve targeted product generation in CO2RR technology.

This review summarizes the recent progress and application of different metal-organic frameworks (MOFs)-derived non-noble metal materials for zinc-air batteries in the past few years.This work gives extensive insights in understanding the relationship between design strategies and structure-activity relationship.The challenges and prospects of MOF-derived oxygen electrocatalysts for zinc-air batteries are proposed.

Hydrazine fuel cells are promising sustainable power sources. However, the high price and limited reserves of noble metal catalysts that promote the sluggish cathodic and anodic electrochemical reactions hinder their practical applications. Reflecting the enhanced diffusion and improved kinetics of nanostructured non-noble metal electrocatalysts, we report an efficient zeolitic-imidazole framework-derived trifunctional electrocatalyst for hydrazine oxidation, oxygen, and hydrogen peroxide reduction. Experimental results and theoretical calculations corroborate that the nanocarbon architecture with abundant Co–N species enhances the electronic interaction and optimizes the energy barriers of anodic hydrazine oxidation and cathodic oxygen reduction. The resulting assembled hydrazine-oxygen fuel cell yields a cell voltage and power density of 0.74 V and 20.5 mW cm–2, respectively. Moreover, benefiting from the liquid–liquid diffusion, the hydrazine–hydrogen peroxide cell shows a boosted cell voltage and power density, corresponding to 1.68 V and 41.0 mW cm–2. This work offers a highly active non-noble metal multifunctional electrocatalyst with a pioneering diffusion philosophy in the liquid electrochemical cells.