Enhancing the catalytic activity of MnO2 via structural phase transition for propane combustion: Promotional role of ionic liquid
Enhancing the catalytic activity of MnO2 via structural phase transition for propane combustion: Promotional role of ionic liquid
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DOI：
10.1016/j.jece.2021.106453
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发表时间：
2021-12
影响因子：
7.7
通讯作者：
Liangwei Sun;Peng Zhao;Yihao Liu;Bangjie Tan;Chaoyi Yu;N. Feng;Lei Wang;H. Wan;G. Guan
中科院分区：
文献类型：
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作者：
Liangwei Sun;Peng Zhao;Yihao Liu;Bangjie Tan;Chaoyi Yu;N. Feng;Lei Wang;H. Wan;G. Guan
采用离子液体辅助水热法合成了一系列二氧化锰，并将其用于丙烷燃烧。选用1-丁基-3-甲基咪唑四氟硼酸盐[BMIM-BF 4]作为结构导向剂，在水热条件下可生成扩展的氢键。这些氢键可用于纳米结构自组装的熵驱动，从而调控晶体的生长。同时，[BMIM-BF 4]的存在可以通过静电和π-π堆积作用与MnO 2中的[MnO 6]八面体发生相互作用，最终导致煅烧后α-MnO 2转变为β-MnO 2。一系列表征结果进一步表明，在离子液体的辅助下，前驱体的形貌由纳米花演变为纳米棒与纳米纤维相连接，比表面积和氧化还原性能也得到了提高。当KMnO 4与离子液体的摩尔比为8：1时，Mn-1-500对丙烷的催化燃烧活性最高。丙烷在Mn-1-500上的T90约为310 °C，比没有离子液体辅助的Mn-0-500低近110 °C。这些结果为开发高性能催化剂提供了一种新的策略。
A series of manganese dioxide have been synthesized by ionic liquid assisted hydrothermal method and used for propane combustion. 1-butyl-3-methylimidazolium tetrafluoroborate [BMIM-BF4] was selected as the structure-directing agent, which could generate extended hydrogen bonds under hydrothermal conditions. These hydrogen bonds could be used for entropy driving of nanostructures self-assembly, thus regulating the growth of crystal. Meanwhile, the existence of [BMIM-BF4] could interact with [MnO6] octahedron in MnO2through electrostatic and π-π stacking interactions, eventually leading to the transformation from α-MnO2to β-MnO2after calcination. A series of characterization results further indicated that with the assistance of ionic liquid, the morphology of the precursor evolved from nanoflowers to nanorods attached with nanofibers, and the specific surface areas and redox properties were also enhanced. When the molar ratio of KMnO4to ionic liquid reached 8:1, the obtained Mn-1–500 exhibited the highest catalytic activity for propane combustion. The T90of propane on Mn-1–500 was about 310 °C, which was nearly 110 °C lower than that of Mn-0–500 prepared without the assistance of ionic liquid. These results could offer a novel strategy for the development of high-performance catalysts.