Wang Juan, Hao Panpan, Shi Ruina, Yang Leilei, Liu Shusen, Zhao Jinxian, Ren Jun, Li Zhong
Key Laboratory of Coal Science and Technology (Taiyuan University of Technology), Ministry of Education and Shanxi Province, No. 79 Yingze West Street, Taiyuan, 030024, China.
Nanoscale Res Lett. 2017 Aug 8;12(1):481. doi: 10.1186/s11671-017-2258-7.
A facile way was developed to fabricate yolk-shell composites with tunable Cu cores encapsulated within hollow carbon spheres (Cu@C) with an average diameter about 210 nm and cavity size about 80 nm. During pyrolysis, the confined nanospace of hollow cavity ensures that the nucleation-and-growth process of Cu nanocrystals take place exclusively inside the cavities. The size of Cu cores can be easily tuned from 30 to 55 nm by varying the copper salt concentration. By deliberately creating shell porosity through KOH chemical activation, at an optimized KOH/HCS mass ratio of 1/4, the catalytic performance for the oxidative carbonylation of methanol to dimethyl carbonate (DMC) of the activated sample is enhanced remarkably with TOF up to 8.6 h at methanol conversion of 17.1%. The activated yolk-shell catalyst shows promising catalytic properties involving the reusability with slight loss of catalytic activity and negligible leaching of activated components even after seven recycles, which is beneficial to the implementation of clean production for the eco-friendly chemical DMC thoroughly.
开发了一种简便的方法来制备具有可调铜核的蛋黄壳复合材料，铜核封装在平均直径约为210 nm、腔尺寸约为80 nm的中空碳球（Cu@C）内。在热解过程中，中空腔的受限纳米空间确保了铜纳米晶体的成核和生长过程仅在腔内发生。通过改变铜盐浓度，可以轻松地将铜核的尺寸从30 nm调整到55 nm。通过KOH化学活化故意制造壳层孔隙率，在优化的KOH/HCS质量比为1/4时，活化样品对甲醇氧化羰基化制碳酸二甲酯（DMC）的催化性能显著提高，在甲醇转化率为17.1%时，TOF高达8.6 h-1。活化的蛋黄壳催化剂显示出有前景的催化性能，包括可重复使用性，即使经过七次循环后催化活性略有损失且活化组分的浸出可忽略不计，这有利于彻底实现环保化学品DMC的清洁生产。
