The high thermal stabilizing capability of noble metals (Pd and Au) supported by SBA-15 and the impact on CO oxidation,New Journal of Chemistry

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The high thermal stabilizing capability of noble metals (Pd and Au) supported by SBA-15 and the impact on CO oxidation
New Journal of Chemistry ( IF 2.7 ) Pub Date : 2021-09-16 , DOI: 10.1039/d1nj02235k
Palle Ramana Murthy _{1,

2} , Jing-Cai Zhang ₂ , Wei-Zhen Li ₂

Affiliation

Precious metal nanoparticles (NPs) are attractive for use in the field of catalysis because of their precisely controlled sizes and shapes. However, NPs exhibit insufficient anti-sintering properties under common operating conditions due to their poor thermal stability at elevated temperatures. In this paper, the preparation of noble metallic NPs (Pd and Au) incorporated inside the pores of an SBA-15 support via a sol-immobilization method, which prevents their aggregation, is reported. The Pd NPs retain their size of ∼5 nm within the channels of SBA-15, even after aging at 800 °C for three days under an air atmosphere. However, Au NPs aggregated at a temperature of calcination above 500 °C. Using a set of characterization methods comprising XRD, STEM, HRTEM, TPR, and DRIFTS analysis, it is revealed that Pd on SBA-15 exhibits better anti-sintering properties than the Au supported system. The catalytic activity and durability of M/SBA-15 (M: Pd or Au) catalysts were studied using CO oxidation with and without steam (10 vol%). Interestingly, a hydrothermally treated (Pd/SBA-15-750-H₂O-3d) catalyst leads to the partial re-dispersion of Pd. This helps to attain smaller particles of ∼1.6 nm, which play a prominent role in the catalytic performance. This work provides insight into the design of sintering-resistant metal catalysts, which would be suitable for industrial applications under harsh conditions.

中文翻译：

SBA-15支持的贵金属（Pd和Au）的高热稳定能力及其对CO氧化的影响

贵金属纳米颗粒 (NPs) 因其精确控制的尺寸和形状而在催化领域具有吸引力。然而，由于它们在高温下的热稳定性差，NPs 在常见的操作条件下表现出不足的抗烧结性能。在本文中，通过在 SBA-15 载体的孔中加入贵金属 NPs（Pd 和 Au）的制备报道了一种防止它们聚集的溶胶固定方法。即使在空气气氛下在 800°C 下老化三天后，Pd NPs 在 SBA-15 的通道内仍保持约 5 nm 的尺寸。然而，Au NPs 在 500 °C 以上的煅烧温度下聚集。使用包括 XRD、STEM、HRTEM、TPR 和 DRIFTS 分析在内的一组表征方法，表明 SBA-15 上的 Pd 表现出比 Au 负载系统更好的抗烧结性能。M/SBA-15 (M: Pd 或 Au) 催化剂的催化活性和耐久性通过使用和不使用蒸汽 (10 vol%) 的 CO 氧化进行研究。有趣的是，水热处理 (Pd/SBA-15-750-H ₂O-3d) 催化剂导致 Pd 的部分再分散。这有助于获得约 1.6 nm 的更小颗粒，这在催化性能中起着重要作用。这项工作为耐烧结金属催化剂的设计提供了见解，该催化剂将适用于恶劣条件下的工业应用。

更新日期：2021-09-16

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