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The spin configuration is vital for oxygen evolution reaction (OER) activity because it has a strong effect on the adsorption/desorption ability of electrochemical reaction intermediates and the electronic properties of the catalyst. Here, we demonstrate the control of crystal facets to raise the Co 3+ spin state in double perovskite PrBaCo 2 O 6 (PBCO) single-crystal thin films and thereby optimize catalytic performance for the OER. The spin configuration of Co 3+ at room temperature was studied in detail. The result indicates that different deformations of the CoO 6 octahedrons induced by different crystal facets increase the Co 3+ spin states. The PBCO(100) films possess stronger adsorption of OER intermediate products, enhancing Co 3d−O 2p hybridization, and faster charge transfer, representing optimal OER activity compared to PBCO(110) and PBCO(111) films. This work deepens our understanding of the relationship between enhanced OER activity and spin configuration of Co ions at room temperature and provides a new design strategy for perovskite oxide catalysts.

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W exsolution induces surface defects, promoting the in situ self-reconstruction and formation of high-valance Ni with superior activity towards HMFOR.

Mg3Al1Zn alloy extruding rods were subjected to rotary forging at temperatures ranging from room temperature to 723 K. The effect of rotary forging on formability, microstructures, and hardness of the samples was investigated. Compared to common forging, rotary forging appeared to significantly promote formability at elevated temperatures, especially at 673 K and 723 K. Dynamic crystallization occurred in both samples prepared at these two temperatures, whereas newly generated grains in the 673 K were much finer. A special tilted basal texture was discovered in both samples, exhibiting strong anistropy, and the hardness in the cross section increased from the center to the edge of the samples.