Influence of MnO2 crystal existing form on its catalytic performance for toluene oxidation
Influence of MnO2 crystal existing form on its catalytic performance for toluene oxidation
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MnO2晶体存在形态对其催化甲苯氧化性能的影响
DOI：
10.1016/j.fuel.2022.126780
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发表时间：
2023
期刊：
影响因子：
7.4
通讯作者：
Wei Chu
中科院分区：
文献类型：
--
作者：
Xuxu Zhai;Luming Li;Shuang Song;Junjun Zhang;Jun Ma;Chongrui Xie;Wei Chu
在温和介质下，通过Mn与羧基之间的桥联作用诱导Mn原位自掺杂，合成了一系列不同晶型的MnO2催化剂，并将其应用于甲苯的催化氧化。 XRD、SEM和TEM结果表明所制备的催化剂的物理结构对Mn/CA的比例极其敏感。只有MnCA-4催化剂具有特殊的形貌，为双晶，为棒状和球状结构的均匀混合，有的为空心棒状结构。由于不同相结构之间的相互作用，双晶混合MnCA-4催化剂具有最佳的甲苯氧化催化性能，在228℃下可以氧化90%的甲苯。 H2-TPR、O2-TPD和XPS的表征证明，不同晶型的氧化锰之间的强相互作用导致产生更多的氧空位和Mn3+物种。原位DRIFTS结果表明，MnCA-4催化剂较MnCA-12催化剂具有更强的吸附和活化甲苯的能力，这可能是其优异的甲苯催化氧化性能的主要原因。该研究为设计高效非贵金属催化剂来构建不同晶型的界面工程提供了有效策略。
A series of MnO2catalysts with different crystal forms were synthesized by in situ self-doping of Mn induced by bridging interaction between Mn and carboxyl group under moderate medium, and applied to catalytic oxidation of toluene. XRD, SEM and TEM results show that the physical structure of the prepared catalyst is extremely sensitive to the ratio of Mn/CA. Only MnCA-4 catalyst has a special morphology with double crystal and a uniform mixture of rod-like and spherical structures, and some of them are hollow rod-like structures. Due to the interaction between different phase structures, the mixed MnCA-4 catalyst with dual crystal has the best catalytic performance of toluene oxidation, which can oxidize 90 % toluene at 228 °C. The characterization of H2-TPR, O2-TPD, and XPS proved that the strong interaction between different crystalline forms of manganese oxide led to the generation of more oxygen vacancies and Mn3+species. In situ DRIFTS results show thatMnCA-4 catalyst has stronger ability to adsorb and activate toluene compared with MnCA-12 catalyst, which may be the main reason for its excellent catalytic oxidation performance of toluene. This study provides an effective strategy for designing high efficiency non-noble metal catalysts to construct interface engineering of different crystal types.