Optimizing the electronic structure with increasing intrinsic stability is a usual method to enhance the catalysts' performance. Herein, a series of cerium dioxide (CeO) based solid solution materials is synthesized via substituting Ce atoms with transition metal (Co, Cu, Ni, etc.), in which CoCeO shows optimized band structure because of electron transition in the reaction, namely Co (3d4s) + Ce (4f5d 6s) → Co (3d4s) + Ce (4f5d6s), with more stable electronic configuration.
View Article and Find Full Text PDFDevelopment of large-scale alkaline seawater electrolysis requires robust and corrosion-resistant anodes. Here we propose engineering NiFe layered double hydroxide (LDH)-based anodes by incorporating a series of anions into the LDH interlayers. The most optimal NiFe LDH anode with intercalated phosphates demonstrates stable operation at a high current density of 1.
View Article and Find Full Text PDFWater splitting hinges crucially on the availability of electrocatalysts for the oxygen evolution reaction. The surface reconstruction has been widely observed in perovskite catalysts, and the reconstruction degree has been often correlated with the activity enhancement. Here, a systematic study on the roles of Fe substitution in activation of perovskite LaNiO is reported.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Inevitable leaching and corrosion under anodic oxidative environment greatly restrict the lifespan of most catalysts with excellent primitive activity for oxygen production. Here, based on Fick' s Law, we present a surface cladding strategy to mitigate Ni dissolution and stabilize lattice oxygen triggering by directional flow of interfacial electrons and strong electronic interactions via constructing elaborately cladding-type NiO/NiS heterostructure with controlled surface thickness. Multiple in situ characterization technologies indicated that this strategy can effectively prevent the irreversible Ni ions leaching and inhibit lattice oxygen from participating in anodic reaction.
View Article and Find Full Text PDFLubricating hydrogel coatings on inert rubber and plastic surfaces significantly reduce friction and wear, thus enhancing material durability and lifespan. However, achieving optimal hydration lubrication typically requires a porous polymer network, which unfortunately reduces their mechanical strength and limits their applicability where robust durability and wear-resistance are essential. In the research, a hydrogel coating with remarkable wear resistance and surface stability is developed by forming a semi-interpenetrating polymer network with polymer substrate at the interface.
View Article and Find Full Text PDFThe utilization of rare earth elements to regulate the interaction between catalysts and oxygen-containing species holds promising prospects in the field of oxygen electrocatalysis. Through structural engineering and adsorption regulation, it is possible to achieve high-performance catalytic sites with a broken activity-stability tradeoff. Herein, this work fabricates a hierarchical CeO/NiCo hydroxide for electrocatalytic oxygen evolution reaction (OER).
View Article and Find Full Text PDFDesign the electrocatalysts without noble metal is still a challenge for oxygen evolution reaction (OER) in acid media. Herein, we reported the manganese (Mn) doping method to decrease the concentration of oxygen vacancy (V) and form the Mn-O structure adjacent octahedral sites in spinel NiCoO (NiMnCoO), which highly enhanced the activity and stability of spinel NiCoO with a low overpotential (η) of 280 mV at j=10 mA cm and long-term stability of 80 h in acid media. The isotopic labelling experiment based on differential electrochemical mass spectrometry (DEMS) clearly demonstrated the lattice oxygen in NiMnCoO is more stable due to strong Mn-O bond and shows synergetic adsorbate evolution mechanism (SAEM) for acid OER.
View Article and Find Full Text PDFThe low coverage rate of anode OH adsorption under high current density conditions has become an important factor restricting the development of an industrial alkaline water electrolyzer (AWE). Here, we present our rare earth modification promotion strategy on using the rare earth oxygen-friendly interface to increase the OH coverage of the NiS surface for efficient AWE anode catalysis. Density functional theory calculations predict that rare earths can enhance the coverage of surface OH, and the synthesis reaction mechanism is discussed in the synthesis process spectrum.
View Article and Find Full Text PDFEffective and robust catalyst is the core of water splitting to produce hydrogen. Here, we report an anionic etching method to tailor the sulfur vacancy (V) of NiS to further enhance the electrocatalytic performance for hydrogen evolution reaction (HER). With the V concentration change from 2.
View Article and Find Full Text PDFThe electronic structure and geometric configuration of catalysts play a crucial role to design novel perovskite-type catalysts for oxygen reduction reaction (ORR). Nowadays, many studies are more concerned with the influence of electronic structure and ignore the geometric effect, which plays a nonnegligible role in enhancing catalytic performances. Herein, this work regulates the MnO octahedral tilting degree of LaMnO by modulating the concentration of Y, excluding the electronic effect from the valence state of manganese.
View Article and Find Full Text PDFIon regulation strategy is regarded as a promising pathway for designing transition metal oxide-based electrocatalysts for oxygen evolution reaction (OER) with improved activity and stability. Precise anion conditioning can accurately change the anionic environment so that the acid radical ions (SO , PO , SeO , etc.), regardless of their state (inside the catalyst, on the catalyst surface, or in the electrolyte), can optimize the electronic structure of the cationic active site and further increase the catalytic activity.
View Article and Find Full Text PDFTo master the activation law and mechanism of surface lattice oxygen for the oxygen evolution reaction (OER) is critical for the development of efficient water electrolysis. Herein, we propose a strategy for triggering lattice-oxygen oxidation and enabling non-concerted proton-electron transfers during OER conditions by substituting Al in LaSrCoO. According to our experimental data and density functional theory calculations, the substitution of Al can have a dual effect of promoting surface reconstruction into active Co oxyhydroxides and activating deprotonation on the reconstructed oxyhydroxide, inducing negatively charged oxygen as an active site.
View Article and Find Full Text PDFMany perovskite oxides (ABO ) are considered the most promising alternatives to noble metal catalysts for oxygen reduction reaction (ORR) due to their high intrinsic activities. However, their electrocatalytic performance is often limited by poor electrical conductivity and low specific surface area. Here an electrochemically induced calcium-leaching process is reported to greatly increase the electrochemical surface area (ECSA) of La Ca MnO (LCMO64).
View Article and Find Full Text PDFAngew Chem Int Ed Engl
November 2023
A highly selective and durable oxygen evolution reaction (OER) electrocatalyst is the bottleneck for direct seawater splitting because of side reactions primarily caused by chloride ions (Cl ). Most studies about OER catalysts in seawater focus on the repulsion of the Cl to reduce its negative effects. Herein, we demonstrate that the absorption of Cl on the specific site of a popular OER electrocatalyst, nickel-iron layered double hydroxide (NiFe LDH), does not have a significant negative impact; rather, it is beneficial for its activity and stability enhancement in natural seawater.
View Article and Find Full Text PDFHydrogen production from electrocatalytic water splitting driven by renewable energy sources provides a promising path for energy sustainability. The current water electrolysis technologies mainly use fresh water as feedstock, which will further aggravate the shortage of water resources in the world. Seawater has an innate advantage in large-scale electrolysis hydrogen production because of its abundant reserves.
View Article and Find Full Text PDFCopper-based electrocatalysts effectively produce multicarbon (C ) compounds during the electrochemical CO reduction (CO RR). However, big challenges still remain because of the chemically unstable active sites. Here, cerium is used as a self-sacrificing agent to stabilize the Cu of CuS, due to the facile Ce /Ce redox.
View Article and Find Full Text PDFOxygen evolution reaction (OER) is one of the important half-reactions in energy conversion equipment such as water-spitting devices, rechargeable metal-air batteries, and so on. It is beneficial to develop efficient and low-cost catalysts that understand the reaction mechanism of OER and analyze the reconstruction phenomenon of transition metal sulfide. Interestingly, copper sulfide and cuprous sulfide with the same components possess different reconstruction behaviors due to their different metal ion valence states and different atomic arrangement modes.
View Article and Find Full Text PDFDynamic reconstruction of metal sulphides during electrocatalytic oxygen evolution reaction (OER) has hampered the acquisition of legible evidence for comprehensively understanding the phase-transition mechanism and electrocatalytic activity origin. Herein, modelling on a series of cobalt-nickel bimetallic sulphides, we for the first time establish an explicit and comprehensive picture of their dynamic phase evaluation pathway at the pre-catalytic stage before OER process. By utilizing the in-situ electrochemical transmission electron microscopy and electron energy loss spectroscopy, the lattice sulphur atoms of (NiCo)S particles are revealed to be partially substituted by oxygen from electrolyte to form a lattice oxygen-sulphur coexisting shell surface before the generation of reconstituted active species.
View Article and Find Full Text PDFNanostructured metal-nitrides have attracted tremendous interest as a new generation of catalysts for electroreduction of CO, but these structures have limited activity and stability in the reduction condition. Herein, we report a method of fabricating FeN/FeN nanoparticles with FeN/FeN interface exposed on the NP surface for efficient electrochemical CO reduction reaction (CORR). The FeN/FeN interface is populated with Fe-N and Fe-N coordination sites respectively that show the desired catalysis synergy to enhance the reduction of CO to CO.
View Article and Find Full Text PDFOriented synthesis of transition metal sulfides (TMSs) with controlled compositions and crystal structures has long been promising for electronic devices and energy applications. Liquid-phase cation exchange (LCE) is a well-studied route by varying the compositions. However, achieving crystal structure selectivity is still a great challenge.
View Article and Find Full Text PDFFormate is identified as economically viable chemical fuel from electrochemical carbon dioxide reduction. However, the selectivity of current catalysts toward formate is limited by the competitive reaction such as HER. Herein, we propose a CeO modification strategy to improve the selectivity of catalysts for formate through tuning of the *OCHO intermediate, which is important for formate production.
View Article and Find Full Text PDFElectrocatalytic reduction of CO to formate is considered as a promising method to achieve carbon neutrality, and the introduction of heteroatoms is an effective strategy to improve the catalytic activity and selectivity of catalysts. However, the structural reconstruction behavior of catalysts driven by voltage is usually ignored. Therefore, we used Cu/BiS as a model to reveal the dynamic reduction process in different atmospheric environments.
View Article and Find Full Text PDFDesigning active and stable oxygen evolution reaction (OER) catalysts are vitally important to various energy conversion devices. Herein, we introduce elements Ni and Mn into (Co) (Co ) O nanosheets (NSs) at fixed geometrical sites, including Mn , Ni , and Ni , to optimize the initial geometrical structure and modulate the CoCo O surface from oxygen-excess to oxygen-deficiency. The pristine (Ni,Mn)-(Co) (Co ) O NSs shows excellent OER activity with an overpotential of 281.
View Article and Find Full Text PDFTuning the structure of the active center of catalysts to atomic level provides the most efficient utilization of the active component, which plays an especially important role for precious metals. In this study, the liquid phase ion exchange method is used to introduce atomic Ir into LaNiO perovskite oxide, which shows excellent catalytic performance in the oxygen evolution reaction (OER). The catalyst, LaNi Ir O , with the optimal concentration of Ir, displays an overpotential of just 280 mV at 10 mA cm .
View Article and Find Full Text PDFThe regulation of mechanism on the electrocatalysis process with multiple reaction pathways is more efficient and essential than conventional material engineering for the enhancement of catalyst performance. Here, by using oxygen evolution reaction (OER) as a model, which has an adsorbate evolution mechanism (AEM) and a lattice oxygen oxidation mechanism (LOM), we demonstrate a general strategy for steering the two mechanisms on various LaSrCoO. By delicately controlling the oxygen defect contents, the dominant OER mechanism on LaSrCoO can be arbitrarily transformed between AEM-LOM-AEM accompanied by a volcano-type activity variation trend.
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