Carbon-carbon(C–C)coupling reactions represent one of the most powerful tools for the synthesis of complex natural products,bioactive molecules developed as drugs and agrochemicals.In this work,a multifunctional nano...Carbon-carbon(C–C)coupling reactions represent one of the most powerful tools for the synthesis of complex natural products,bioactive molecules developed as drugs and agrochemicals.In this work,a multifunctional nanoreactor for C–C coupling reaction was successfully fabricated via encapsulating the core-shell Cu@Ni nanocubes into ZIF-8(Cu@Ni@ZIF-8).In this nanoreactor,Ni shell of the core-shell Cu@Ni nanocubes was the catalytical active center,and Cu core was in situ heating source for the catalyst by absorbing the visible light.Moreover,benefiting from the plasmonic resonance effect between Cu@Ni nanocubes encapsulated in ZIF-8,the absorption range of nanoreactor was widened and the utilization rate of visible light was enhanced.Most importantly,the microporous structure of ZIF-8 provided shape-selective of reactant.This composite was used for the highly shape-selective and stable photocatalysed C–C coupling reaction of boric acid under visible light irradiation.After five cycles,the nanoreactor still remained high catalytical activity.This Cu@Ni@ZIF-8 nanoreactor opens a way for photocatalytic C–C coupling reactions with shape-selectivity.展开更多
Toluene methylation with methanol offers an alternative method to produce p-xylene by gathering methyl group directly from C1 chemical sources. It supplies a ＂molecular engineering＂ process to realize directional co...Toluene methylation with methanol offers an alternative method to produce p-xylene by gathering methyl group directly from C1 chemical sources. It supplies a ＂molecular engineering＂ process to realize directional conversion of toluene/methanol molecules by selective catalysis in complicated methylation system. In this review, we introduce the synthesis method ofp-xylene, the development history of methylation catalysts and reaction mechanism, and the effect of reaction condition in para-selective technical process. If constructing p-xylene as the single target product, the major challenge to develop para-selective toluene methylation is to improve the p-xylene selectivity without, or as little as possible, losing the fraction of methanol for methylation. To reach higher yield ofp-xylene and more methanol usage in methylation, zeolite catalyst design should consider improving mass transfer and afterwards coveting external acid sites by surface modification to get short ＂micro-tunnels＂ with shape selectivity. A solid understanding of mass transfer will benefit realizing the aim of converting more methanol feedstock into para-methyl group.展开更多
基金We gratefully acknowledge the financial support from the Beijing Natural Science Foundation(No.2182061)Science Foundation of China University of Petroleum,Bejing(No.2462019BJRC001).
文摘Carbon-carbon(C–C)coupling reactions represent one of the most powerful tools for the synthesis of complex natural products,bioactive molecules developed as drugs and agrochemicals.In this work,a multifunctional nanoreactor for C–C coupling reaction was successfully fabricated via encapsulating the core-shell Cu@Ni nanocubes into ZIF-8(Cu@Ni@ZIF-8).In this nanoreactor,Ni shell of the core-shell Cu@Ni nanocubes was the catalytical active center,and Cu core was in situ heating source for the catalyst by absorbing the visible light.Moreover,benefiting from the plasmonic resonance effect between Cu@Ni nanocubes encapsulated in ZIF-8,the absorption range of nanoreactor was widened and the utilization rate of visible light was enhanced.Most importantly,the microporous structure of ZIF-8 provided shape-selective of reactant.This composite was used for the highly shape-selective and stable photocatalysed C–C coupling reaction of boric acid under visible light irradiation.After five cycles,the nanoreactor still remained high catalytical activity.This Cu@Ni@ZIF-8 nanoreactor opens a way for photocatalytic C–C coupling reactions with shape-selectivity.
基金Acknowledgements We would like to greatly acknowledge the financial support from the National Natural Science Foundation of China （NSFC, Grant No. 21403303） and Major Research Plan of NSFC （No. 91434102）.
文摘Toluene methylation with methanol offers an alternative method to produce p-xylene by gathering methyl group directly from C1 chemical sources. It supplies a ＂molecular engineering＂ process to realize directional conversion of toluene/methanol molecules by selective catalysis in complicated methylation system. In this review, we introduce the synthesis method ofp-xylene, the development history of methylation catalysts and reaction mechanism, and the effect of reaction condition in para-selective technical process. If constructing p-xylene as the single target product, the major challenge to develop para-selective toluene methylation is to improve the p-xylene selectivity without, or as little as possible, losing the fraction of methanol for methylation. To reach higher yield ofp-xylene and more methanol usage in methylation, zeolite catalyst design should consider improving mass transfer and afterwards coveting external acid sites by surface modification to get short ＂micro-tunnels＂ with shape selectivity. A solid understanding of mass transfer will benefit realizing the aim of converting more methanol feedstock into para-methyl group.
