Nanoparticles-based catalysts still suffer from deactivation due to sintering and structural collapse through long-time running at high reaction temperature. Developing simple strategy for improving the sintering resistance of nanoparticles is of great importance for fabrication of durable heterogeneous catalysts. In this work, lanthanum was used to prevent CoO nanoparticles from sintering with restricting growth of nanocrystals by in-situ generation of LaCoO perovskite phase during thermal ageing process, further building LaCoO-CoO hetero-interface with strong interfacial effect. Specifically, the CoO nanocatalyst was loaded with different amount of La by traditional impregnation method and a series of characterizations were carried out to explore the physical and chemical properties of the as-prepared catalysts, including XRD, Raman, BET, SEM, HRTEM, XPS, H-TPR and O-TPD. It was found that 5 wt% La-CoO has the highest catalytic activity in CH combustion and the value of T (temperature of 90% methane conversion) between fresh and aged was only 9 ºC, while this value was 108 ºC over pure CoO sample. The Raman, XPS, H-TPR and O-TPD results exhibited that the synergistic effect between CoO and LaCoO could not only induce lattice distortion in CoO with more defects and adsorbed oxygen species, enhanced oxygen mobility and reducibility, but also significantly suppress the growth of CoO nanocrystals during thermal ageing treatment.

中文翻译：

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镧改性Co3O4纳米催化剂上LaCoO3-Co3O4异质界面的原位重构可提高甲烷燃烧中的催化活性和抗烧结性

纳米粒子基催化剂在高反应温度下长时间运行仍然会因烧结和结构崩溃而失活。开发简单的策略来提高纳米粒子的耐烧结性对于制造耐用的多相催化剂非常重要。在这项工作中，利用镧在热老化过程中原位生成LaCoO钙钛矿相，防止CoO纳米粒子烧结，限制纳米晶体的生长，进一步构建具有强界面效应的LaCoO-CoO异质界面。具体而言，通过传统的浸渍方法在CoO纳米催化剂上负载不同量的La，并进行了一系列表征，以探索所制备的催化剂的物理和化学性质，包括XRD、Raman、BET、SEM、HRTEM、XPS 、H-TPR 和 O-TPD。结果发现，5 wt% La-CoO 在 CH 燃烧中具有最高的催化活性，新鲜和老化之间的 T 值（90% 甲烷转化温度）仅为 9 ℃，而该值比纯 CoO 样品高 108 ℃ 。 Raman、XPS、H-TPR 和 O-TPD 结果表明，CoO 和 LaCoO 之间的协同作用不仅可以引起具有更多缺陷和吸附氧物种的 CoO 晶格畸变，增强氧迁移率和还原性，而且可以显着抑制生长CoO纳米晶在热老化处理过程中的变化。