当前位置：
X-MOL 学术
›
Chem. Mater.
›
论文详情
Our official English website, www.x-mol.net, welcomes your
feedback! (Note: you will need to create a separate account there.)
Evolution of Exsolved Nanoparticles on a Perovskite Oxide Surface during a Redox Process
Chemistry of Materials ( IF 7.2 ) Pub Date : 2018-03-29 00:00:00 , DOI: 10.1021/acs.chemmater.8b01029 Ke-Yu Lai 1 , Arumugam Manthiram 1
Chemistry of Materials ( IF 7.2 ) Pub Date : 2018-03-29 00:00:00 , DOI: 10.1021/acs.chemmater.8b01029 Ke-Yu Lai 1 , Arumugam Manthiram 1
Affiliation
|
To evaluate the self-regeneration feasibility of exsolved Co–Fe nanoparticles on the La0.3Sr0.7Cr0.3Fe0.6Co0.1O3−δ perovskite at intermediate operation temperature (700 °C), the evolution of surface morphology and particle phases during a redox process has been determined by scanning and transmission electron microscopy. Unlike the complete reincorporation of the exsolved metals back to the perovskite lattice at 800 °C during the reoxidation process, the transition-metal oxide remains on the surface as an intermediate phase because of a sluggish reincorporation rate at 700 °C. Although the transition-metal oxide particles grow and coarsen quickly in an oxidizing atmosphere, the nanoparticles could still be formed by a disintegration of the reduced spinel oxide in a reducing atmosphere. The hemispherical-like shape of the nanoparticles can be achieved by minimizing metallic surface energy and maintaining the strong metal–oxide interaction. The redispersion of Co–Fe nanoparticles completes the self-regeneration process at 700 °C. The exsolved nanoparticle size distribution is strongly affected by temperature but not by a redox process, which improves performance stability and reactivation at the relatively lower temperature during long-term operation.
中文翻译：
氧化还原过程中钙钛矿氧化物表面上溶解的纳米颗粒的演化
评估溶解的Co-Fe纳米粒子在La 0.3 Sr 0.7 Cr 0.3 Fe 0.6 Co 0.1 Co 0.1 O 3−δ上的自我再生可行性钙钛矿在中间操作温度（700°C）下，已通过扫描和透射电子显微镜确定了氧化还原过程中表面形态和颗粒相的演变。与再氧化过程中溶解的金属在800°C下完全重新掺入钙钛矿晶格不同，过渡金属氧化物由于在700°C下的缓慢掺入率而保留在表面上作为中间相。尽管过渡金属氧化物颗粒在氧化气氛中快速生长和粗化，但仍可以通过在还原气氛中还原的尖晶石氧化物的分解来形成纳米颗粒。纳米粒子的半球形形状可以通过最大程度地减少金属表面能并保持强大的金属-氧化物相互作用来实现。Co-Fe纳米粒子的再分散在700°C的温度下完成了自再生过程。溶解的纳米颗粒尺寸分布受温度的强烈影响，但不受氧化还原过程的影响，这可改善性能稳定性和长期运行期间在较低温度下的活化。
更新日期：2018-03-29
中文翻译：
氧化还原过程中钙钛矿氧化物表面上溶解的纳米颗粒的演化
评估溶解的Co-Fe纳米粒子在La 0.3 Sr 0.7 Cr 0.3 Fe 0.6 Co 0.1 Co 0.1 O 3−δ上的自我再生可行性钙钛矿在中间操作温度（700°C）下，已通过扫描和透射电子显微镜确定了氧化还原过程中表面形态和颗粒相的演变。与再氧化过程中溶解的金属在800°C下完全重新掺入钙钛矿晶格不同，过渡金属氧化物由于在700°C下的缓慢掺入率而保留在表面上作为中间相。尽管过渡金属氧化物颗粒在氧化气氛中快速生长和粗化，但仍可以通过在还原气氛中还原的尖晶石氧化物的分解来形成纳米颗粒。纳米粒子的半球形形状可以通过最大程度地减少金属表面能并保持强大的金属-氧化物相互作用来实现。Co-Fe纳米粒子的再分散在700°C的温度下完成了自再生过程。溶解的纳米颗粒尺寸分布受温度的强烈影响，但不受氧化还原过程的影响，这可改善性能稳定性和长期运行期间在较低温度下的活化。
京公网安备 11010802027423号