Development of efficient and affordable electrocatalysts in neutral solutions is paramount importance for the renewable energy. Herein, we report that the oxygen evolution reaction (OER) performance of Co3 S4 under neutral conditions can be enhanced by exposed octahedral planes and self-adapted spin states in atomically thin nanosheets. A HAADF image clearly confirmed that the active octahedra with Jahn-Teller distortions were exposed exclusively. Most importantly, in the atomically thin nanosheets, the spin states of Co(3+) in the octahedral self-adapt from low-spin to high-spin states. As a result, the synergistic effect endow the Co3 S4 nanosheets with superior OER performance, with exceptional low onset overpotentials of circa 0.31 V in neutral solutions, which is state-of-the-art among inorganic non-noble metal compounds.

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Development of efficient and affordable electrocatalysts in neutral solutions is paramount importance for the renewable energy.Herein, we report that the oxygen evolution reaction (OER) performance of Co 3 S 4 under neutral conditions can be enhanced by exposed octahedral planes and selfadapted spin states in atomically thin nanosheets.AHAADF image clearly confirmed that the active octahedra with JahnTeller distortions were exposed exclusively.M ost importantly, in the atomically thin nanosheets,the spin states of Co 3+ in the octahedral self-adapt from low-spin to high-spin states.A s aresult, the synergistic effect endow the Co 3 S 4 nanosheets with superior OER performance,w ith exceptional low onset overpotentials of circa 0.31 Vinneutral solutions,which is state-ofthe-art among inorganic non-noble metal compounds.

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Strong metal–support interaction (SMSI) is a phenomenon commonly observed on heterogeneous catalysts. Here, direct evidence of SMSI between noble metal and 2D TiB2 supports is reported. The temperature‐induced TiB2 overlayers encapsulate the metal nanoparticles, resulting in core–shell nanostructures that are sintering‐resistant with metal loadings as high as 12.0 wt%. The TiOx‐terminated TiB2 surfaces are the active sites catalyzing the dehydrogenation of formic acid at room temperature. In contrast to the trade‐off between stability and activity in conventional SMSI, TiB2‐based SMSI promotes catalytic activity and stability simultaneously. By optimizing the thickness and coverage of the overlayer, the Pt/TiB2 catalyst displays an outstanding hydrogen productivity of 13.8 mmol g−1cat h−1 in 10.0 m aqueous solution without any additive or pH adjustment, with >99.9% selectivity toward CO2 and H2. Theoretical studies suggest that the TiB2 overlayers are stabilized on different transition metals through an interplay between covalent and electrostatic interactions. Furthermore, the computationally determined trends in metal–TiB2 interactions are fully consistent with the experimental observations regarding the extent of SMSI on different transition metals. The present research introduces a new means to create thermally stable and catalytically active metal/support interfaces for scalable chemical and energy applications.

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This work is devoted to functional ARMA(p, q) processes and approximating vector models based on functional PCA in the context of prediction. After deriving sufficient conditions for the existence of a stationary solution to both the functional and the vector model equations, the structure of the approximating vector model is investigated. The stationary vector process is used to predict the functional process. A bound for the difference between vector and functional best linear predictor is derived. The paper concludes by applying functional ARMA processes for the modeling and prediction of highway traffic data.

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