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Infrared Reflection Absorption Spectroscopy (IRRAS) has been applied to study the nature of the co-ordination of Nafion® to a Pt electrode surface. The experiments have been carried out using a Pt electrode coated with a thin film of Nafion® assembled into a thin layer spectroelectrochemical cell. The potential modulation or the subtractively normalized interfacial Fourier transform infrared reflection spectroscopy (SNIFTIRS) experiments have been performed, in order to distinguish between the bulk properties of the Nafion® membrane and the properties of the membrane at the interace with the Pt electrode. The results showed that the interaction between the membrane and a Pt electrode resembles the interaction between a Pt electrode and a sulfuric acid solution.

Fe nanocrystal catalysts were synthesized by electrochemistry. Shape transformations of Fe nanocrystals from rhombic dodecahedra and tetragonal bipyramids, both bounded by {110} facets, to 18-facet polyhedra enclosed by different combinations of {101} and {100} facets and finally to cubes exclusively covered by {100} facets have been achieved. A study of the surface-structure functionality of the Fe nanocrystats toward electroreduction of nitrite revealed that the etectrocatalytic activity of the Fe nanocrystats increases as the fraction of {100} facets on the surface of the Fe NCs increases.NSFC [20833005, 20873113, 20873116]; MOST [2007DFA40890]; Fujian Key Project [200810025

Pt triambic icosahedral nanocrystals (TIH NCs) enclosed by {771} high-index facets were successfully synthesized electrochemically, for the first time, in ChCl-urea based deep eutectic solvents, and exhibited higher electrocatalytic activity and stability towards ethanol electrooxidation than a commercial Pt black catalyst.

Oxygen redox at high-voltage has emerged as a transformative paradigm for high-energy battery cathodes by offering extra capacity beyond conventional transition-metal redox. However, it suffers from voltage hysteresis, voltage fade, and capacity drop upon cycling. Here, we show that, by eliminating the domain boundaries in the often-considered single-crystalline battery particles, layered oxide cathodes demonstrate exceptional capacity and voltage stability during high-voltage operation. Our combined experimental and theory studies for the first time reveal that the elimination of domain boundaries could enhance the reversible lattice oxygen redox while inhibiting the irreversible oxygen release, leading to significantly suppressed structural degradation and improved mechanical integrity during battery cycling and abuse heating. The robust oxygen redox enabled through domain boundary control provides practical opportunities towards high-energy, long-cycling, and safe batteries. MainHigh-energy batteries rely on high-capacity and high-voltage operation of the cathodes.Fundamentally, the capacity of a transition metal oxide-based cathode is determined by the amount of active Li, while the voltage is defined by the redox reactions affected by structural configurations 1 . This has led to two associated trends in recent cathode development: Li-excess compounds due to the large amount of Li (capacity) and oxygen redox (OR) at high-voltage 2-6 .However, intensive studies have shown that OR activities can trigger detrimental structural effects such as oxygen release, surface reactions, and phase transition, leading to severe voltage hysteresis, voltage fade, and poor capacity stability 3,5 . Despite extensive mechanistic understanding 3,5 and material optimization such as structural control [7][8][9] , chemical composition manipulation 10 , and cationic/anionic doping [11][12][13] , the fundamental origin of the OR instability remains under active debate, and the practical control of high-voltage operation involving OR remains a formidable challenge. The key relies on a strategy that enhances the reversible OR in the lattice, while suppressing or even eliminating other detrimental oxygen activities.Theoretical studies suggest that the surface could favour the migration of oxygen ions and promote the formation of oxygen vacancies due to the open atomic structure [14][15][16] . Therefore, surface-initiated irreversible oxygen loss and the associated structural transformation have long been considered as the root cause of the capacity decay and voltage fade of Li-excess layered cathodes when activating the OR process [16][17][18] . However, surface coatings to mitigate the oxygen loss have proven insufficient to achieve a fully reversible OR 5,18,19 .Grain boundaries (GBs), the surface that separates individual grains from each other, play a vital role in materials' properties. In layered oxide cathodes, the GBs have been predominantly referred to the boundaries between primary particles of polycrystalline cathodes, while ...