钴原子团簇用于高效氧还原反应

探索非贵金属材料作为高效氧还原反应催化剂是迫切需要的,但具有一定的挑战性。本文采用等离子体轰击和酸洗相结合的策略合成了Co原子团簇修饰的多孔碳载体催化剂(CoAC/NC)。通过多种表征手段证实了的原子团簇特征。所得到的CoAC/NC催化剂在三电极体系和锌-空电池方面都表现出优异的氧还原反应活性。该催化剂的氧还原反应半波电位为0.887 V,显著优于商业Pt/C催化剂,且表现出优异的稳定性。此外,该催化剂组装的锌-空电池的峰值功率密度为181.5 m W·cm^(-2),同样远高于Pt/C催化剂。这项工作不仅合成了一种高效的氧还原反应催化剂,而且为原子团簇催化剂的理性设计和实际应用提供了新的见解。

Engineering Ruthenium-Based Electrocatalysts for Effective Hydrogen Evolution Reaction

The investigation of highly effective,durable,and cost-effective electrocatalysts for the hydrogen evolution reaction(HER)is a prerequisite for the upcoming hydrogen energy society.To establish a new hydrogen energy system and gradually replace the traditional fossil-based energy,electrochemical water-splitting is considered the most promising,environmentally friendly,and efficient way to produce pure hydrogen.Compared with the commonly used platinum(Pt)-based catalysts,ruthenium(Ru)is expected to be a good alternative because of its similar hydrogen bonding energy,lower water decomposition barrier,and considerably lower price.Analyzing and revealing the HER mechanisms,as well as identifying a rational design of Ru-based HER catalysts with desirable activity and stability is indispensable.In this review,the research progress on HER electrocatalysts and the relevant describing parameters for HER performance are briefly introduced.Moreover,four major strategies to improve the performance of Ru-based electrocatalysts,including electronic effect modulation,support engineering,structure design,and maximum utilization(single atom)are discussed.Finally,the challenges,solutions and prospects are highlighted to prompt the practical applications of Rubased electrocatalysts for HER.

In-situ Generation of Hydroxyl Layers in Coo@FeSe_(2) Catalyst for High Selectivity Seawater Electrolysis

Seawater electrolysis holds great promise for hydrogen production in the future,while the development of anodic catalysts has been severely hampered by the side-reaction,chloride evolution reaction.In this work,nano-flower-cluster structured Coo@FeSe_(2)/CF catalysts are synthesized via a scalable electrodeposition technique,and the performance is systematically studied.The oxygen evolution reaction(OER)overpotential of Co0@FeSe_(2)/CF is 267 mV at 100 mA.cm^(-2),which is significantly lower than that of the IrO_(2) catalyst(435 mV).Additionally,the catalyst shows high selectivity for OER(97.9%)and almost no loss of activity after a durability test for 1100 h.The impressive performance is attributed to the dense rod-like structure with abundant active centers after electrochemical activation and the in-situ generated CoOOH and FeOOH that improve the catalytic activity of the catalyst.The synergistic effect induced bythenon-uniform structureendows the catalyst with excellent stability.

Introducing sulfur to nickel-iron selenide for high-efficiency alkaline seawater electrolysis

Seawater electrolysis is an effective way to obtain hydrogen(H_(2))in a sustainable manner.However,the lack of electrocatalysts with high activity,stability,and selectivity for oxygen evolution reaction(OER)severely hinders the development of seawater electrolysis technology.Herein,sulfur-doped nickel-iron selenide nanosheets(S-NiFeSe_(2))were prepared by an ion-exchange strategy and served as highly active OER electrocatalyst for alkaline seawater electrolysis.The overpotential is 367 m V,and it can run stably for over 50 h at 100 m A cm^(-2).Excitingly,the S-NiFeSe_(2)||Pt/C pair exhibits cell voltage of 1.54 V at 10 m A cm^(-2)under alkaline seawater conditions,which can run smoothly for 100 h without decay,and the efficiency of electricity-tohydrogen(ETH)energy conversion reaches more than 80%.Such electrode,with abundant accessible reactive sites and good corrosion resistance,is a good candidate for seawater electrolysis.Moreover,density functional theory calculations reveal that the surface sulfur atoms can activate the adjacent Ni sites and decrease the free energy changes of the associated intermediates at the adjacent Ni sites for OER,and the step of~*OH→~*O is the potential rate-limiting step.In this work,the true reactive site in nickel-iron selenides is the Ni sites,but not the Fe sites as commonly believed.