Chemical Sciences Division and Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
Angew Chem Int Ed Engl. 2017 Aug 7;56(33):9820-9824. doi: 10.1002/anie.201704656. Epub 2017 Jul 19.
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 SrTiO (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 TiO . 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 BaZrO , thus highlighting the generality of the findings of this study.
尽管钙钛矿已被广泛应用于催化领域，但对其表面终止来控制反应选择性的调控尚未得到很好的建立。在这项研究中，我们采用了多种表面敏感技术来表征 SrTiO（STO）在热预处理（Sr 富集）和化学刻蚀（Ti 富集）后的表面终止（表面重构的一个方面）。我们通过使用 2-丙醇的转化作为探针反应，表明 STO 的表面终止可以被控制以极大地调变催化酸碱性质，并因此在很宽的范围内调变反应选择性，这是单一金属氧化物（SrO 或 TiO）无法实现的。密度泛函理论（DFT）计算很好地解释了具有不同表面终止的 STO 上的选择性调谐和反应机制。在 BaZrO 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。
