Gold catalysis had been considered a highly efficient candidate for heterogeneous catalysis.It is well established that reducible-material-supported Au NPs are more reactive than the unreducible materials,unless speci...Gold catalysis had been considered a highly efficient candidate for heterogeneous catalysis.It is well established that reducible-material-supported Au NPs are more reactive than the unreducible materials,unless specific modifications are carried out.However,unreducible materials such as carbon materials,silica,and alumina have particular advantages,including the easily controlled surface property,adjustable microscopic structure,earth-abundant reserves,and facile industrial manufacture.New strategies,influences,and mechanisms of modification to enhance the catalytic performance and thermal stability of unreducible-material-supported gold catalysts are among the most attractive research topics in gold catalysis.However,to the best of our knowledge,reports and reviews focused on unreducible-material-supported gold catalysts are lacking.Herein,the above concept will be thoroughly discussed regarding several typical unreducible supports,including the commonly used silica,alumina,carbon materials,and hydroxyapatite.The currently prevailing modification strategies will be summarized in detail from the aspects of theoretical conceptualization and practical methodology,including the ingenious synthesis method for catalyst with a specific structure,the currently prosperous electrostatic adsorption,colloid immobilization,and the applicative thermal gaseous treatment.The influences of physical and chemical modifications on the surface chemistry,electronic structure,interaction/synergy between Au-support/promoter,catalyst morphology and water precipitation will be also summarized.It is assumed that the review will shed light on significant studies on unreducible support in gold catalysis with the purpose of catalytic promotion and the promotion of the potential industrial demands in advance.Furthermore,the review will provide new insights into unreducible supports that can be potentially applied in gold catalysis.展开更多
In the last few years,the overall incidence of malignant tumors has been increasing in the country.In order to find effective anti-tumor drugs,the development and modification of natural drugs have become the focus of...In the last few years,the overall incidence of malignant tumors has been increasing in the country.In order to find effective anti-tumor drugs,the development and modification of natural drugs have become the focus of domestic and international researchers.Thallus japonica,composed of polysaccharides,minerals,amino acids,natural proteins,and lipids,is a traditional Chinese medicine with the functions of eliminating phlegm and disinhibiting water.At the same time,it has the edible and medicinal efficacy.There are a lot of active components that have been demonstrated to possess diverse biological activities including anti-tumor,anti-viral,anti-coagulant,and anti-bacterial,and so on in thallus japonica.Laminarin,composed of glucose,galactose,fucose and so on,is a common and high molecular weight heteropolysaccharide in brown algae(such as thallus japonica,kelp),and it is a potential anti-tumor drug.However,the lack of biological activity of natural polysaccharides limits the application of polysaccharides,so it is necessary to modify the structure or physical and chemical properties of it to enhance the anti-tumor activity of polysaccharides.In recent years,in order to improve the biological activity of laminarin,domestic and international researchers have introduced some groups on the surface of it.Moreover,use the function of modified groups to cause the changes in physicochemical property,spatial structure,substituent group and molecular weight to improve the anti-tumor activity in vitro and in vivo.Therefore,the structural modification has become the main and powerful means to improve the activity of polysaccharides.展开更多
文摘Gold catalysis had been considered a highly efficient candidate for heterogeneous catalysis.It is well established that reducible-material-supported Au NPs are more reactive than the unreducible materials,unless specific modifications are carried out.However,unreducible materials such as carbon materials,silica,and alumina have particular advantages,including the easily controlled surface property,adjustable microscopic structure,earth-abundant reserves,and facile industrial manufacture.New strategies,influences,and mechanisms of modification to enhance the catalytic performance and thermal stability of unreducible-material-supported gold catalysts are among the most attractive research topics in gold catalysis.However,to the best of our knowledge,reports and reviews focused on unreducible-material-supported gold catalysts are lacking.Herein,the above concept will be thoroughly discussed regarding several typical unreducible supports,including the commonly used silica,alumina,carbon materials,and hydroxyapatite.The currently prevailing modification strategies will be summarized in detail from the aspects of theoretical conceptualization and practical methodology,including the ingenious synthesis method for catalyst with a specific structure,the currently prosperous electrostatic adsorption,colloid immobilization,and the applicative thermal gaseous treatment.The influences of physical and chemical modifications on the surface chemistry,electronic structure,interaction/synergy between Au-support/promoter,catalyst morphology and water precipitation will be also summarized.It is assumed that the review will shed light on significant studies on unreducible support in gold catalysis with the purpose of catalytic promotion and the promotion of the potential industrial demands in advance.Furthermore,the review will provide new insights into unreducible supports that can be potentially applied in gold catalysis.
文摘In the last few years,the overall incidence of malignant tumors has been increasing in the country.In order to find effective anti-tumor drugs,the development and modification of natural drugs have become the focus of domestic and international researchers.Thallus japonica,composed of polysaccharides,minerals,amino acids,natural proteins,and lipids,is a traditional Chinese medicine with the functions of eliminating phlegm and disinhibiting water.At the same time,it has the edible and medicinal efficacy.There are a lot of active components that have been demonstrated to possess diverse biological activities including anti-tumor,anti-viral,anti-coagulant,and anti-bacterial,and so on in thallus japonica.Laminarin,composed of glucose,galactose,fucose and so on,is a common and high molecular weight heteropolysaccharide in brown algae(such as thallus japonica,kelp),and it is a potential anti-tumor drug.However,the lack of biological activity of natural polysaccharides limits the application of polysaccharides,so it is necessary to modify the structure or physical and chemical properties of it to enhance the anti-tumor activity of polysaccharides.In recent years,in order to improve the biological activity of laminarin,domestic and international researchers have introduced some groups on the surface of it.Moreover,use the function of modified groups to cause the changes in physicochemical property,spatial structure,substituent group and molecular weight to improve the anti-tumor activity in vitro and in vivo.Therefore,the structural modification has become the main and powerful means to improve the activity of polysaccharides.
