Although perovskites have been widely used in catalysis, tuning of their surface termination to control reaction selectivity has not been well established. In this study, we employed multiple surface-sensitive techniques to characterize the surface termination (one aspect of surface reconstruction) of SrTiO₃ (STO) after thermal pretreatment (Sr enrichment) and chemical etching (Ti enrichment). We show, by using the conversion of 2-propanol as a probe reaction, that the surface termination of STO can be controlled to greatly tune catalytic acid/base properties and consequently the reaction selectivity over a wide range, which is not possible with single-metal oxides, either SrO or TiO₂. Density functional theory (DFT) calculations explain well the selectivity tuning and reaction mechanism on STO with different surface termination. Similar catalytic tunability was also observed on BaZrO₃, thus highlighting the generality of the findings of this study.

中文翻译：

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通过钙钛矿催化剂的表面终止控制反应选择性

尽管钙钛矿已广泛用于催化中，但尚未很好地调节其表面终止以控制反应选择性。在这项研究中，我们采用了多种表面敏感技术来表征热预处理（Sr富集）和化学蚀刻（Ti富集）后SrTiO ₃（STO）的表面终止（表面重建的一个方面）。我们通过使用2-丙醇的转化作为探针反应表明，可以控制STO的表面终止，以极大地调节催化酸/碱的性质，因此可以在很宽的范围内选择反应，这对于单金属氧化物，SrO或TiO ₂。密度泛函理论（DFT）的计算很好地解释了具有不同表面终止条件的STO的选择性调整和反应机理。在BaZrO ₃上也观察到了类似的催化可调性，从而突出了本研究结果的普遍性。