The 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. Plotting the MnO octahedral tilting degree as a function of concentration of Y produces a volcano-shaped plot. The octahedral tilting can reduce the Mn-O covalency, generating more highly active Mn and oxygen vacancies during ORR process. The specific activity has a positive correlation with octahedral tilting degree. Meanwhile, the octahedral tilting stabilizes Mn-O interactions during ORR process and promote stability. Based on experimental results and DFT calculations, octahedral tilting alters the rate-determining step (RDS) and decrease the energy barrier. Subsequent extended experiment confirms that octahedral tilting is the key factor to affect the catalytic performances.
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http://dx.doi.org/10.1002/adma.202311102 | DOI Listing |
ACS Mater Au
January 2025
Beijing National Laboratory for Molecular Science, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
Two-dimensional lead iodide perovskites have attracted significant attention for their potential applications in optoelectronic and photonic devices due to their tunable excitonic properties. The choice of organic spacer cations significantly influences the light emission and exciton transport properties of these materials, which are vital for their device performance. In this Perspective, we discuss the impact of spacer cations on lattice dynamics and exciton-phonon coupling, focusing on three representative 2D lead iodide perovskites that exhibit distinct types of structural distortions.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
State Key Laboratory of Precision Electronic Manufacturing Technology and Equipment, Guangdong Provincial Research Center on Smart Materials and Energy Conversion Devices, Guangdong Provincial Key Laboratory of Functional Soft Condensed Matter, School of Materials and Energy, School of Electromechanical Engineering and School of Integrated Circuits, Guangdong University of Technology, Guangzhou 510006, China.
Lead-based antiferroelectric (AFE) ceramics have the advantages of high power density, fast charge and discharge speed, and the electric-field-induced AFE-FE phase transition, making them one of the potential dielectric energy storage materials. However, the energy storage density still needs to be improved. In this work, (PbCa) (ZrSn)O (PCZS, = 0.
View Article and Find Full Text PDFInorg Chem
December 2024
Facultad de Farmacia, Departamento de Química y Bioquímica, Urbanización Montepríncipe, Universidad San Pablo-CEU, CEU Universities, Boadilla del Monte, E-28668 Madrid, Spain.
Lanthanum strontium ferrite (LaSrAgFeO = 0; LSFO) and its silver-doped derivative (LaSrAgFeO = 0.05; LASFO) are synthesized using mild conditions by a sol-gel method. Both oxides present a perovskite-like structure with orthorhombic symmetry due to octahedral tilting; thus, the incorporation of silver in the A-site does not significantly modify the perovskite structure.
View Article and Find Full Text PDFJ Colloid Interface Sci
March 2025
School of Chemistry and Chemical Engineering, Guizhou Key Laboratory for Green Chemical and Clean Energy Technology, Guizhou University, Guiyang, Guizhou 550025, China; Department of Brewing Engineering, Moutai Institute, Renhuai 564501, China; College of Chemistry and Materials Engineering, Liupanshui Normal University, Liupanshui 553004, China. Electronic address:
Direct synthesis of hydrogen peroxide (DSHP) from oxygen (O) and hydrogen (H) offers a promising alternative to anthraquinone oxidation for hydrogen peroxide (HO) production, yet challenges remain in achieving high selectivity and productivity. In this study, palladium octahedral nanoparticles (Pd ONPs) exposing Pd(111) facets were first synthesized, followed by the introduction of lead (Pb) atoms onto these facets to construct Pb-Pd(111) surface alloy structures (Pd@Pd-Pbx ONPs) for efficient DSHP. Characterization results indicated that the introduction of Pb atoms increased the electron density of Pd atoms and significantly reduced the number of low-coordinated Pd atoms.
View Article and Find Full Text PDFAdv Mater
November 2024
State Key Laboratory of Advanced Chemical Power Sources, Frontiers Science Center for New Organic Matter, Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), College of Chemistry, Nankai University, Tianjin, 300071, P. R. China.
Pure-halide reduced-dimensional perovskites, featuring large exciton binding energy and tunable bandgap, show great potential for high-efficiency deep-blue perovskite light-emitting diodes (PeLEDs). However, their efficiency, particularly in the low n-value phase domain ("n" represents the number of octahedral sheets), lags behind analogous perovskite emitters. Herein, it is demonstrated that the vibration of edge-dangling octahedra in the low n-value phase activates notorious exciton-phonon (EP) coupling, thereby deteriorating efficiency.
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