原位限域生长策略制备有序介孔碳负载的超小MoO3纳米颗粒

采用原位限域生长策略制备了一系列有序介孔碳负载的超小MoO₃纳米颗粒复合物(OMC-US-MoO₃). 其中, 有序介孔碳被用作基质来原位限域MoO₃纳米晶的生长. 依此方法制备的MoO₃纳米晶具有超小的晶粒尺寸(<5 nm), 并在介孔碳骨架内具有良好的分散度. 制得的OMC-US-MoO₃复合物具有可调的比表面积(428~796 m²/g)、 孔容(0.27~0.62 cm³/g)、 MoO₃质量分数(4%~27%)和孔径(4.6~5.7 nm). 当MoO₃纳米晶的质量分数为7%时, 所得样品OMC-US-MoO₃-7具有最大的孔径、 最小的孔壁厚度和最规整的介观结构. 该样品作为催化剂时, 表现出优异的环辛烯选择性氧化性能.

In situ Confinement Growth Strategy for Ordered Mesoporous Carbon Support Ultrasmall MoO3 Nanoparticles

Ultrasmall particle sizes and excellent dispersity of the MoO₃ active species on support majorly dominate their catalytic performances. Herein， a series of ordered mesoporous carbon support ultrasmall molybdena nanoparticles（OMC-US-MoO₃） composites was synthesized through an in situ confinement growth strategy. Ordered mesoporous carbon was used as the matrix to in situ confine the growth of MoO₃ nanocrystals. The obtained MoO₃ nanocrystals show ultrasmall particle sizes（<5 nm） and excellent dispersity on the meso- porous carbon frameworks. The obtained OMC-US-MoO₃ exhibits tunable specific surface areas（428―796 m²/g）， pore volumes（0.27―0.62 cm³/g）， MoO₃ contents（4%―27%， mass fraction） and uniform pore sizes（4.6―5.7 nm）. As a typical example， the obtained sample with 7% MoO₃（denoted as OMC-US-MoO₃-7） shows the largest pore size， smallest thickness of pore wall and most regular mesostructures. When being used as a catalyst， the OMC-US-MoO₃-7 exhibits an excellent catalytic activity for selective oxidation of cyclooctene with a high stability.