摘要
Mass transfer and catalyst recovery are two crucial issues in solid base catalysis,while the cumbersome operation steps and the associated time and energy penalties are still inevitable for conventional catalysts.Achieving the technical upgrades through catalyst design is desirable but challenging because of the difficulty in satisfying diverse demands of different steps.In this work,a magnetically responsive solid base catalyst with the rod-like nanostructure was developed.The rod-like solid base catalysts are composed of Fe_(3)O_(4) cores,silica shells and calcium oxide active sites.The functions of magnetic recovery and stirring were integrated into the catalyst,which applies in both the general catalytic processes and microchannel reactors given their nanoscales.When applied to the synthesis of dimethyl carbonate by onestep transesterification of methanol and ethylene carbonate,an apparent enhancement on turnover frequency value(33.1 h^(−1))was observed for nano-stirring compared with that tested without stirring(12.1 h^(−1))within 30 min.The present catalysts may open up new avenues in the development of advanced solid base catalysts.
传质和催化剂回收是固体碱催化中的两个关键问题,而对于传统催化剂而言,繁琐的操作步骤以及相关的时间和能量损耗仍然是不可避免的.通过催化剂设计实现技术升级是可取的,但由于难以同时满足不同步骤的不同需求,其仍具有挑战性.在本项工作中,我们开发了一种具有棒状纳米结构的磁响应固体碱催化剂.该棒状固体碱催化剂是由Fe_(3)O_(4)内核、二氧化硅外壳和氧化钙活性位点构成的,且同时集成了磁性回收和搅拌功能.考虑到其纳米尺寸,这一功能集成的催化剂能够同时适用于常规的催化过程和微通道反应器.当将此催化剂应用于催化甲醇和碳酸乙烯酯的一步酯交换合成碳酸二甲酯时,在30 min内,纳米搅拌下催化转换频率的数值(33.1 h^(−1))明显高于未搅拌下的(12.1 h^(−1)).本催化剂可能为开发先进的固体碱催化剂开辟新的途径.
基金
supported by the National Natural Science Foundation of China Youth Project(21808110)
the financial support of this work by the National Science Fund for Distinguished Young Scholars(22125804)
the National Natural Science Foundation of China(21878149,22078155,and 21722606)。
