Østergaard Martin B, Deganello Francesca, La Parola Valeria, Liotta Leonarda F, Boffa Vittorio, Jørgensen Mads K
Department of Chemistry and Bioscience, Center for Membrane Technology, Aalborg University Aalborg East 9220 Denmark
Istituto per lo Studio dei Materiali Nanostrutturati, Consiglio Nazionale delle Ricerche Via Ugo La Malfa 153 90146 Palermo Italy
RSC Adv. 2023 Jul 17;13(31):21459-21470. doi: 10.1039/d3ra03404f. eCollection 2023 Jul 12.
Ce-doped SrFeO perovskite-type compounds are known as good thermocatalysts for the abatement of wastewater contaminants of emerging concern. In this work, SrCeFeO-CeO perovskite-oxide systems with increasing amounts of cerium excess (0, 5, 10 and 15 mol% Ce), with respect to its maximum solubility in the perovskite, were prepared in one-pot by solution combustion synthesis and the effects of cerium excess on the chemical physical properties and thermocatalytic activity in the bisphenol A degradation were evaluated. The powders were characterized by powder X-ray diffraction combined with Rietveld refinement, X-ray photoelectron spectroscopy, thermal gravimetry, temperature programmed reduction, nitrogen adsorption, scanning electron microscopy and energy dispersive X-ray spectroscopy techniques. Results highlight that the perovskite structural, redox, surface, and morphological properties are affected by the co-growth of the main perovskite phase and ceria and that a larger cerium excess has a beneficial effect on the thermocatalytic performance of the perovskite oxide-ceria biphasic system, although ceria is not active as a thermocatalyst itself. Perovskite properties and performance are enhanced by the tetragonal distortion induced by the introduction of cerium excess in the synthesis. It is supposed that a larger oxygen mobility and an easier reducibility are among the most relevant features that contribute to superior thermocatalytic properties of these perovskite oxide-based systems. These results also suggest new perspectives in the nanocomposite preparation and their catalytic applications.
铈掺杂的SrFeO钙钛矿型化合物是用于去除新出现的废水中污染物的优良热催化剂。在本工作中，通过溶液燃烧合成法一锅制备了铈过量（相对于其在钙钛矿中的最大溶解度，铈过量分别为0、5、10和15 mol%）含量增加的SrCeFeO-CeO钙钛矿氧化物体系，并评估了铈过量对双酚A降解过程中化学物理性质和热催化活性的影响。采用粉末X射线衍射结合Rietveld精修、X射线光电子能谱、热重分析、程序升温还原、氮气吸附、扫描电子显微镜和能量色散X射线光谱技术对粉末进行了表征。结果表明，主要钙钛矿相和二氧化铈的共生长会影响钙钛矿的结构、氧化还原、表面和形态性质，并且尽管二氧化铈本身作为热催化剂不具有活性，但较大的铈过量对钙钛矿氧化物-二氧化铈双相体系的热催化性能具有有益影响。在合成过程中引入铈过量所引起的四方畸变增强了钙钛矿的性能和表现。据推测，更大的氧迁移率和更容易的还原性是这些基于钙钛矿氧化物的体系具有优异热催化性能的最相关特征。这些结果也为纳米复合材料的制备及其催化应用提供了新的视角。
