Tailoring Facets of α-Mn2O3 Microcrystalline Catalysts for Enhanced Selective Oxidation of Glycerol to Glycolic Acid
Tailoring Facets of α-Mn2O3 Microcrystalline Catalysts for Enhanced Selective Oxidation of Glycerol to Glycolic Acid
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DOI：
10.1021/acscatal.1c01566
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发表时间：
2021-06
期刊：
影响因子：
12.9
通讯作者：
Hao Yan;Qiyu Shen;Yinghao Sun;Si-ming Zhao;Ruilong Lu;Meng Gong;Yibin Liu;Xin Zhou;Xin Jin;Xiang Feng;Xiaobo Chen;De Chen;Chaohe Yang
中科院分区：
文献类型：
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作者：
Hao Yan;Qiyu Shen;Yinghao Sun;Si-ming Zhao;Ruilong Lu;Meng Gong;Yibin Liu;Xin Zhou;Xin Jin;Xiang Feng;Xiaobo Chen;De Chen;Chaohe Yang
了解和调整催化剂晶面相关的催化性能对于多元醇的选择氧化具有重要意义。在本论文中，我们成功地合成了一系列不同形貌的α-Mn2O催化剂(八面体、截面体和立方体)，用于甘油选择氧化制乙醇酸的强化反应。结果表明，不同形貌的Mn2O_3催化剂的催化性能差异源于(001)晶面和(111)晶面的化学性质。多重表征和密度泛函理论计算表明，(001)面上的表面氧空位与催化活性有很好的相关性，并且含氧中间体中的C-H键很容易被(001)面上的表面氧空位激活，从而提高了催化活性。此外，(111)面的主要作用是防止乙醇酸产物的过氧化，从而提高乙醇酸的选择性。因此，同时具有(001)和(111)晶面的Mn2O3截断八面体催化剂具有较高的催化活性(0.87 mmol/(Hm2))和乙醇酸选择性(52.6%)。我们期望这项工作能为甘油氧化体系中高效廉价催化剂的设计提供一些建议。
Understanding and tuning the crystal-facet-dependent catalytic properties of catalysts are of great importance for the selective oxidation of polyols. Herein, a series of α-Mn2O3catalysts with various morphologies (octahedron, truncated octahedron, and cube) are successfully synthesized for the enhanced selective oxidation of glycerol to glycolic acid. Our results show that the different catalytic performances of Mn2O3catalysts with various morphologies originated from the chemical nature of the (001) and (111) facets. Multicharacterizations and density functional theory calculations revealed that the surface oxygen vacancies on the (001) facets are well correlated with the catalytic activity, and the C–H bond in oxygen-containing intermediates could be easily activated on the surface oxygen vacancies of the (001) facets, thus improving the catalytic activity. Moreover, the main role of (111) facets is to prevent the over-oxidation of glycolic acid products, leading to the improvement of glycolic acid selectivity. Consequently, the Mn2O3-truncated octahedron catalyst with both (001) and (111) facets shows high catalytic activity (0.87 mmol/(h m2)) and glycolic acid selectivity (52.6%) simultaneously. We anticipate that this work could give some suggestions for the design of highly efficient inexpensive catalysts in the glycerol oxidation system.