The development of catalytic materials for the recycling CO_(2) through a myriad of available processes is an attractive field,especially given the current climate change.While there is increasing publication in this ...The development of catalytic materials for the recycling CO_(2) through a myriad of available processes is an attractive field,especially given the current climate change.While there is increasing publication in this field,the reported catalysts rarely deviate from the traditionally supported metal nanoparticle morphology,with the most simplistic method of enhancement being the addition of more metals to an already complex composition.Encapsulated catalysts,especially yolk@shell catalysts with hollow voids,offer answers to the most prominent issues faced by this field,coking and sintering,and further potential for more advanced phenomena,for example,the confinement effect,to promote selectivity or offer greater protection against coking and sintering.This work serves to demonstrate the current position of catalyst development in the fields of thermal CO_(2) reforming and hydrogenation,summarizing the most recent work available and most common metals used for these reactions,and how yolk@shell catalysts can offer superior performance and survivability in thermal CO_(2) reforming and hydrogenation to the more traditional structure.Furthermore,this work will briefly demonstrate the bespoke nature and highly variable yolk@shell structure.Moreover,this review aims to illuminate the spatial confinement effect and how it enhances yolk@shell structured nanoreactors is presented.展开更多
In heterogeneous catalysis,the precise placement of active components to perform unique functions in cooperation with each other is a tremendous challenge.The migration of matter on micro/nano-scale caused by diffusio...In heterogeneous catalysis,the precise placement of active components to perform unique functions in cooperation with each other is a tremendous challenge.The migration of matter on micro/nano-scale caused by diffusion is a promising pathway for design of catalytic nanoreactors with precise active sites location and controllable microenvironment through compartmentalization and confinement effects.Herein,we report two categories of mesoporous ZnCoSiOx hollow nanoreactors with different metal distributions and microenvironment engineered by the diffusion behavior of metal species in confined nanospace.Double-shelled hollow structures with well-distributed metal species were obtained by adopting core@shell structured ZnCo-zeolitic imidazolate framework(ZIF)@SiO2 as a template and employing three stages of hydrothermal treatment including the decomposition of ZIF,diffusion of metal species into the silica shell,and Ostwald ripening.Additionally,the formation of yolk@shell structure with a collective(Zn-Co)metal oxide as the yolk was achieved by direct pyrolysis of ZnCo-ZIF@SiO2.In CO_(2)hydrogenation,ZnCoSiOx with double-shelled hollow structures and yolk@shell structures respectively afford CO and CH_(4)as main product,which is related with different dispersion and location of active sites in the two catalysts.This study provides an efficient method for the synthesis of catalytic nanoreactors on the basis of insights of the atomic diffusion in confined space at the mesoscale.展开更多
基金Financial support was provided by the Chinese Academy of Sciences–The World Academy of Sciences(CAS-TWAS)president fellowship。
文摘The development of catalytic materials for the recycling CO_(2) through a myriad of available processes is an attractive field,especially given the current climate change.While there is increasing publication in this field,the reported catalysts rarely deviate from the traditionally supported metal nanoparticle morphology,with the most simplistic method of enhancement being the addition of more metals to an already complex composition.Encapsulated catalysts,especially yolk@shell catalysts with hollow voids,offer answers to the most prominent issues faced by this field,coking and sintering,and further potential for more advanced phenomena,for example,the confinement effect,to promote selectivity or offer greater protection against coking and sintering.This work serves to demonstrate the current position of catalyst development in the fields of thermal CO_(2) reforming and hydrogenation,summarizing the most recent work available and most common metals used for these reactions,and how yolk@shell catalysts can offer superior performance and survivability in thermal CO_(2) reforming and hydrogenation to the more traditional structure.Furthermore,this work will briefly demonstrate the bespoke nature and highly variable yolk@shell structure.Moreover,this review aims to illuminate the spatial confinement effect and how it enhances yolk@shell structured nanoreactors is presented.
基金supported by the National Natural Science Foundation of China(No.22005296)the Natural Science Foundation of Liaoning Province,China(No.2020-YQ-01)the LiaoNing Revitalization Talents Program,China(No.XLYC1807077).
文摘In heterogeneous catalysis,the precise placement of active components to perform unique functions in cooperation with each other is a tremendous challenge.The migration of matter on micro/nano-scale caused by diffusion is a promising pathway for design of catalytic nanoreactors with precise active sites location and controllable microenvironment through compartmentalization and confinement effects.Herein,we report two categories of mesoporous ZnCoSiOx hollow nanoreactors with different metal distributions and microenvironment engineered by the diffusion behavior of metal species in confined nanospace.Double-shelled hollow structures with well-distributed metal species were obtained by adopting core@shell structured ZnCo-zeolitic imidazolate framework(ZIF)@SiO2 as a template and employing three stages of hydrothermal treatment including the decomposition of ZIF,diffusion of metal species into the silica shell,and Ostwald ripening.Additionally,the formation of yolk@shell structure with a collective(Zn-Co)metal oxide as the yolk was achieved by direct pyrolysis of ZnCo-ZIF@SiO2.In CO_(2)hydrogenation,ZnCoSiOx with double-shelled hollow structures and yolk@shell structures respectively afford CO and CH_(4)as main product,which is related with different dispersion and location of active sites in the two catalysts.This study provides an efficient method for the synthesis of catalytic nanoreactors on the basis of insights of the atomic diffusion in confined space at the mesoscale.
