This study reveals the transport behavior of lattice water during proton (de)insertion in the structure of the hexagonal WO·0.6HO electrode. By monitoring the mass evolution of this electrode material via electrochemical quartz crystal microbalance, we discovered (1) WO·0.6HO incorporates additional lattice water when immersing in the electrolyte at open circuit voltage and during initial cycling; (2) The reductive proton insertion in the WO hydrate is a three-tier process, where in the first stage 0.25 H is inserted per formula unit of WO while simultaneously 0.25 lattice water is expelled; then in the second stage 0.30 naked H is inserted, followed by the third stage with 0.17 HO inserted per formula unit. Ex situ XRD reveals that protonation of the WO hydrate causes consecutive anisotropic structural changes: it first contracts along the c-axis but later expands along the ab planes. Furthermore, WO·0.6HO exhibits impressive cycle life over 20 000 cycles, together with appreciable capacity and promising rate performance.
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http://dx.doi.org/10.1021/jacs.8b03959 | DOI Listing |
Nat Commun
January 2025
Department of Chemistry and Research Institute for Natural Sciences, Korea University, Seoul, Republic of Korea.
The success of proton exchange membrane water electrolysis (PEMWE) depends on active and robust electrocatalysts to facilitate oxygen evolution reaction (OER). Heteroatom-doped-RuO has emerged as a promising electrocatalysts because heteroatoms suppress lattice oxygen participation in the OER, thereby preventing the destabilization of surface Ru and catalyst degradation. However, identifying suitable heteroatoms and achieving their atomic-scale coupling with Ru atoms are nontrivial tasks.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Zhejiang University, Department of Chemistry, CHINA.
Ruthenium dioxide (RuO2) is a benchmark electrocatalyst for proton exchange membrane water electrolyzers (PEMWE), but its stability during the oxygen evolution reaction (OER) is often compromised by lattice oxygen involvement and metal dissolution. Despite that the typical synthesis of RuO2 produces chloride residues, the underlying function of chloride have not well investigated. In this study, we synthesized chlorine-containing RuO2 (RuO2-Cl) and pure RuO2 catalysts with similar morphology and crystallinity.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), State Key Laboratory of Chemical Engineering, Haihe Laboratory of Sustainable Chemical Transformations, Tianjin Key Laboratory of Applied Catalysis Science and Engineering, School of Chemical Engineering & Technology, Tianjin University, Tianjin, 300072, P. R. China.
CO hydrogenation to methanol using green hydrogen derived from renewable resources provides a promising method for sustainable carbon cycle but suffers from high selectivity towards byproduct CO. Here, we develop an efficient PdZn-ZnO/TiO catalyst by engineering lattice dislocation structures of TiO support. We discover that this modification orders irregularly arranged atoms in TiO to stabilize crystal lattice, and consequently weakens electronic interactions with supported active phases.
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, Shaanxi Key Laboratory for Advanced Energy Devices, Shaanxi Engineering Lab for Advanced Energy Technology, School of Materials Science and Engineering, Shaanxi Normal University, Xi'an, 710119, P. R. China.
Understanding the oxygen evolution reaction (OER) mechanism is pivotal for improving the overall efficiency of water electrolysis. Despite methylammonium lead halide perovskites (MAPbX) have shown promising OER performance due to their soft-lattice nature that allows lattice-oxygen oxidation of active α-PbO layer surface, the role of A-site MA or X-site elements in the electrochemical reconstruction and OER mechanisms has yet to be explored. Here, it is demonstrated that the OER mechanism of perovskite@zeolite composites is intrinsically dominated by the A-site group of lead-halide perovskites, while the type of X-site halogen is crucial for the reconstruction kinetics of the composites.
View Article and Find Full Text PDFJ Phys Chem Lett
January 2025
DST Unit of Nanoscience (DST UNS) and Thematic Unit of Excellence (TUE), Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India.
Clathrate hydrates (CHs) are believed to exist in cold regions of space, such as comets and icy moons. While spectroscopic studies have explored their formation under similar laboratory conditions, direct structural characterization using diffraction techniques has remained elusive. We present the first electron diffraction study of tetrahydrofuran (THF) and 1,3-dioxolane (DIOX) CHs in the form of nanometer-thin ice films under an ultrahigh vacuum at cryogenic temperatures.
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