Phosphate-assisted synthesis of ultrathin and thermally stable alumina nanosheets as robust Pd support for catalytic combustion of propane
Phosphate-assisted synthesis of ultrathin and thermally stable alumina nanosheets as robust Pd support for catalytic combustion of propane
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DOI：
10.1016/j.apcatb.2021.119949
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发表时间：
2021-06
影响因子：
22.1
通讯作者：
Qingqing Wu;Jiaorong Yan;Mingxiang Jiang;Qiguang Dai;Jinyan Wu;M. Ha;Qingping Ke;Xingyi Wang;Wangcheng Zhan
中科院分区：
文献类型：
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作者：
Qingqing Wu;Jiaorong Yan;Mingxiang Jiang;Qiguang Dai;Jinyan Wu;M. Ha;Qingping Ke;Xingyi Wang;Wangcheng Zhan
二维γ-Al 2 O3纳米片具有丰富的五配位Al 3+中心，通过金属与载体之间的强相互作用，可以很好地稳定贵金属，是近年来研究的热点。然而，合成高稳定性和高热稳定性的Al 2 O3具有挑战性。在此，我们报告了一种有效的方法来合成具有规则的叶状结构以及高热稳定性的Al 2 O3纳米片。提出了一种新的插层-溶胀-剥离的途径来解释片状结构的形成，然后通过磷酸盐诱导的溶解-生长来进一步调节其形貌/厚度。同时，磷酸盐的存在进一步增强了Al 2 O3纳米片的热稳定性，这是由于磷酸盐占据或耗尽了高反应活性位点和表面羟基。随后，将具有中等锚定位置的热稳定γ-Al 2 O3纳米片用作Pd的载体，并用于丙烷的催化燃烧。Pd/Al 2 O3纳米片对丙烷燃烧具有上级催化活性，在300 °C以下完全转化，更重要的是，Pd/Al 2 O3纳米片具有优异的耐高温性能（1000 °C），这归因于Pd颗粒的再分散和高温下金属-载体间的强相互作用（SMSI）。
Two-dimensional γ-Al2O3nanosheet with rich pentacoordinate Al3+sites which can nicely stabilize noble metalsviastrong interactions between metal and support has been focused. However, the synthesis of ultrathin and highly thermal-stable Al2O3is challenging. Herein, we report an effective approach to synthesize ultrathin Al2O3nanosheets with regular leaf-like architecture as well as high thermal-stability. A novel intercalation-swelling-exfoliation pathway was proposed to elucidate the formation of ultrathin sheet-like structure and then its morphology/thickness could be further adjustedviaa dissolution-growth induced by phosphate. Meanwhile, the presence of phosphate further enhanced thermal stability of Al2O3nanosheets due to the occupation or depletion of high-reactive sites and surface hydroxy groups. Subsequently, the thermally stable γ-Al2O3nanosheets with moderate anchoring sites was used as a support of Pd and investigated for catalytic combustion of propane. The Pd/Al2O3nanosheet exhibited a superior catalytic activity for propane combustion and the complete conversion was below 300 °C, more importantly, the outstanding resistance to high temperature (1000 °C) was observed, which was ascribed to the re-dispersion of Pd particles and the occurrence of strong metal-support interaction (SMSI) at high temperature.