Precisely tuning the spacing of the active centers on the atomic scale is of great significance to improve the catalytic activity and deepen the understanding of the catalytic mechanism,but still remains a challenge.H...Precisely tuning the spacing of the active centers on the atomic scale is of great significance to improve the catalytic activity and deepen the understanding of the catalytic mechanism,but still remains a challenge.Here,we develop a strategy to dilute catalytically active metal interatomic spacing(d_(M-M))with light atoms and discover the unusual adsorption patterns.For example,by elevating the content of boron as interstitial atoms,the atomic spacing of osmium(d_(Os-Os))gradually increases from 2.73 to 2.96?.More importantly,we find that,with the increase in dOs-Os,the hydrogen adsorption-distance relationship is reversed via downshifting d-band states,which breaks the traditional cognition,thereby optimizing the H adsorption and H_2O dissociation on the electrode surface during the catalytic process;this finally leads to a nearly linear increase in hydrogen evolution reaction activity.Namely,the maximum dOs-Os of 2.96?presents the optimal HER activity(8 mV@10 mA cm^(-2))in alkaline media as well as suppressed O adsorption and thus promoted stability.It is believed that this novel atomic-level distance modulation strategy of catalytic sites and the reversed hydrogen adsorption-distance relationship can shew new insights for optimal design of highly efficient catalysts.展开更多
A series of nano-size gold catalysts were prepared by deposition-precipitation method using silica material promoted with different amounts of MgO as the carrier. The influences of MgO addition on the structure and pr...A series of nano-size gold catalysts were prepared by deposition-precipitation method using silica material promoted with different amounts of MgO as the carrier. The influences of MgO addition on the structure and property of the nano-size gold catalysts were characterized by X-ray diffraction （XRD）, transmission electron microscopy （TEM）, O2 temperature-programmed desorption （O2-TPD）, and inductively coupled with plasma atomic emission spectroscopy （ICP-AES） techniques. The total oxidation of CO was chosen as the probe reaction. The results suggest that for the gold catalysts supported on the silica material after MgO modification, the size of the gold particles is pronouncedly reduced, the oxygen mobility is enhanced, and the catalytic activity for low-temperature CO oxidation is greatly improved. The gold catalyst modified by 6 wt% MgO （Mg/SiO2 weight ratio） shows higher CO oxidation activity, over which the temperature of CO total oxidation is lower about 150 K than that over the silica directly supported gold catalyst.展开更多
The isolated secondary metabolites from 39 edible mushrooms are reported,among which 107 compounds were active,61 demonstrated antitubercular activities with IC_(50) range of 0.2-50μg/mL and 46 manifested antimalaria...The isolated secondary metabolites from 39 edible mushrooms are reported,among which 107 compounds were active,61 demonstrated antitubercular activities with IC_(50) range of 0.2-50μg/mL and 46 manifested antimalarial effects with IC_(50) range of 0.061-36μg/mL.While more than 2000 strains of edible mushrooms are identified,this review shows the paucity of research in these rich organisms featuring a vital culinary ingredient worldwide.A thorough search was conducted on basidiomycetes to discuss the chemistry and biology of the isolated compounds,structure activity relationships(SAR)as well as the cytotoxicity profiles of,primarily,the active anti-plasmodial and antitubercular molecules.With a safe cellular profile,lanostane triterpenoids were found to be the only molecules with combined activities against both diseases.SAR correlations reviewed here indicated the significance of 3β-and 7α-hydroxylation in the anti-tuberculosis activity and the terminal unsaturated moiety between C-4 and C-28 in the antimalarial activity in the same terpene skeleton.This review will attract the attention of medicinal chemists,and food scientists to optimize and rationalize the use of mushrooms both as unexploited sources of novel molecules and as nutraceuticals to treat two of the deadliest infectious diseases,malaria,and tuberculosis.展开更多
基金financially sponsored by the National Natural Science Foundation of China(Grant Nos.22075223,22179104)the State Key Laboratory of Advanced Technology for Materials Synthesis and Processing(Wuhan University of Technology)(2022-ZD-4)。
文摘Precisely tuning the spacing of the active centers on the atomic scale is of great significance to improve the catalytic activity and deepen the understanding of the catalytic mechanism,but still remains a challenge.Here,we develop a strategy to dilute catalytically active metal interatomic spacing(d_(M-M))with light atoms and discover the unusual adsorption patterns.For example,by elevating the content of boron as interstitial atoms,the atomic spacing of osmium(d_(Os-Os))gradually increases from 2.73 to 2.96?.More importantly,we find that,with the increase in dOs-Os,the hydrogen adsorption-distance relationship is reversed via downshifting d-band states,which breaks the traditional cognition,thereby optimizing the H adsorption and H_2O dissociation on the electrode surface during the catalytic process;this finally leads to a nearly linear increase in hydrogen evolution reaction activity.Namely,the maximum dOs-Os of 2.96?presents the optimal HER activity(8 mV@10 mA cm^(-2))in alkaline media as well as suppressed O adsorption and thus promoted stability.It is believed that this novel atomic-level distance modulation strategy of catalytic sites and the reversed hydrogen adsorption-distance relationship can shew new insights for optimal design of highly efficient catalysts.
基金supported by the Youth Fund Project(2002B25)of Sichuan Department of Educationthe Scientific Research Foundation for Doctor from Yibin College of China(2010B12)
文摘A series of nano-size gold catalysts were prepared by deposition-precipitation method using silica material promoted with different amounts of MgO as the carrier. The influences of MgO addition on the structure and property of the nano-size gold catalysts were characterized by X-ray diffraction （XRD）, transmission electron microscopy （TEM）, O2 temperature-programmed desorption （O2-TPD）, and inductively coupled with plasma atomic emission spectroscopy （ICP-AES） techniques. The total oxidation of CO was chosen as the probe reaction. The results suggest that for the gold catalysts supported on the silica material after MgO modification, the size of the gold particles is pronouncedly reduced, the oxygen mobility is enhanced, and the catalytic activity for low-temperature CO oxidation is greatly improved. The gold catalyst modified by 6 wt% MgO （Mg/SiO2 weight ratio） shows higher CO oxidation activity, over which the temperature of CO total oxidation is lower about 150 K than that over the silica directly supported gold catalyst.
基金supported by two grants(UIC202007 and UIC202107)from BNU-HKBU United International College.
文摘The isolated secondary metabolites from 39 edible mushrooms are reported,among which 107 compounds were active,61 demonstrated antitubercular activities with IC_(50) range of 0.2-50μg/mL and 46 manifested antimalarial effects with IC_(50) range of 0.061-36μg/mL.While more than 2000 strains of edible mushrooms are identified,this review shows the paucity of research in these rich organisms featuring a vital culinary ingredient worldwide.A thorough search was conducted on basidiomycetes to discuss the chemistry and biology of the isolated compounds,structure activity relationships(SAR)as well as the cytotoxicity profiles of,primarily,the active anti-plasmodial and antitubercular molecules.With a safe cellular profile,lanostane triterpenoids were found to be the only molecules with combined activities against both diseases.SAR correlations reviewed here indicated the significance of 3β-and 7α-hydroxylation in the anti-tuberculosis activity and the terminal unsaturated moiety between C-4 and C-28 in the antimalarial activity in the same terpene skeleton.This review will attract the attention of medicinal chemists,and food scientists to optimize and rationalize the use of mushrooms both as unexploited sources of novel molecules and as nutraceuticals to treat two of the deadliest infectious diseases,malaria,and tuberculosis.
