We see significant progress in the preparation of nanoreactors that host incompatible catalysts for cascade reactions,yet their preparation typically requires specialized,multistep synthetic routes.Here,we utilize cor...We see significant progress in the preparation of nanoreactors that host incompatible catalysts for cascade reactions,yet their preparation typically requires specialized,multistep synthetic routes.Here,we utilize core-satellite microparticles as a versatile strategy for the site isolation of catalysts in core and satellites.The core-satellite clusters are prepared by mixing specific amounts of negatively charged core microparticles(e.g.,acid catalyst)with positively charged satellites(e.g.,base catalyst).Core and satellite are made from incompatible polymers allowing solvent-annealing of clusters into different morphologies(raspberry,patchy,and core-shell)while maintaining site isolation of the catalysts.The core-satellite microparticles show very good catalytic activity in a model one-pot acid/base cascade reaction with subtle differences regarding particle morphology.Raspberry microparticles thereby demonstrated the highest reaction rate and yield,likely due to an alleviated diffusion pathway for the reactants.Finally,we show that this colloidal engineering strategy can be extended to multifunctional microparticles suitable to perform multistep cascade reactions in one pot.展开更多
It is reported for the first time that the Pt/C catalyst can be prepared with a new and simple organic sol method using SnCl2 as the reductant. It was found that the average size of the Pt particles in the Pt/C cataly...It is reported for the first time that the Pt/C catalyst can be prepared with a new and simple organic sol method using SnCl2 as the reductant. It was found that the average size of the Pt particles in the Pt/C catalysts could be controlled with controlling the preparation conditions. The effect of the average sizes of the Pt particles in the Pt/C catalysts obtained with this method on the electrocatalytical activity of the oxidation of methanol was investigated.展开更多
The relationship of the electric conductivity of single and multi component of colloidal catalyst FeCl3 Al(i Bu)3 Phen with their concentration was studied in hydrogenated gasoline solvent at 25℃ ,meanwhile,the UV Vi...The relationship of the electric conductivity of single and multi component of colloidal catalyst FeCl3 Al(i Bu)3 Phen with their concentration was studied in hydrogenated gasoline solvent at 25℃ ,meanwhile,the UV Vis spectra of the corresponding component of the catalyst were detected.The experimental results showed that Al(i Bu)3 existed in associated state and dissociated into ion couple.The reaction between Al(i Bu)3 and FeCl3 was the main reaction to form colloidal core.The Fe(III) on the surface of the colloidal particles was reduced to lower valence by Al(i Bu)3.The stable complex formed by the reaction between Phen and Fe(II) could prevent Fe(II) from being reduced to lower valence.The colloidal particles were comparatively stable by means of the electric double layer yielded by a proper excess of Al(i Bu)3.The stable colloidal particles could be formed in the optimal ratio of the catalyst components.展开更多
The purpose of this work is the study the ability of the plant material Aloe vera to act as natural coagulant using raw water obtained from a drinking water treatment plant(Mila,Algeria).Different solvents such as:NaC...The purpose of this work is the study the ability of the plant material Aloe vera to act as natural coagulant using raw water obtained from a drinking water treatment plant(Mila,Algeria).Different solvents such as:NaCl;NaOH and HCl were used as chemical activators to extract the active components from the Aloe vera plant,and different coagulation-flocculation experiments were conducted in a jar test apparatus to evaluate the perfor-mance of the extracted coagulant.Also,the effect of coagulant dose on some water parameters such as turbidity,pH,total alkalinity and organic matter were investigated.The results showed that the use of coagulants obtained by using different solvents increases the coagulation efficiency compared to the coagulant obtained from the raw material,for example the maximum turbidity removal efficiency was 28.23,78.07,83.46 and 85.15%when using powdered Aloe vera(raw material),AV-NaCl(0.5 M),AV-NaOH(0.05 M)and AV-HCl(0.05 M),respectively.The results defined,that the residual turbidity obtained in this work,where the Aloe vera was used(after treat-ment by solvents)produced a turbidity lower than the Algerian standard(5 NTU)with initial turbidity(13 NTU).In this study,the infrared spectrum study and analysis has revealed the presence of different functional groups,which are responsible for the coagulation process.展开更多
基金a result of a generous grant from the German Research Foundation(DFG)through the Emmy Noether Program(grant number no.GR 5075/2-1).
文摘We see significant progress in the preparation of nanoreactors that host incompatible catalysts for cascade reactions,yet their preparation typically requires specialized,multistep synthetic routes.Here,we utilize core-satellite microparticles as a versatile strategy for the site isolation of catalysts in core and satellites.The core-satellite clusters are prepared by mixing specific amounts of negatively charged core microparticles(e.g.,acid catalyst)with positively charged satellites(e.g.,base catalyst).Core and satellite are made from incompatible polymers allowing solvent-annealing of clusters into different morphologies(raspberry,patchy,and core-shell)while maintaining site isolation of the catalysts.The core-satellite microparticles show very good catalytic activity in a model one-pot acid/base cascade reaction with subtle differences regarding particle morphology.Raspberry microparticles thereby demonstrated the highest reaction rate and yield,likely due to an alleviated diffusion pathway for the reactants.Finally,we show that this colloidal engineering strategy can be extended to multifunctional microparticles suitable to perform multistep cascade reactions in one pot.
文摘It is reported for the first time that the Pt/C catalyst can be prepared with a new and simple organic sol method using SnCl2 as the reductant. It was found that the average size of the Pt particles in the Pt/C catalysts could be controlled with controlling the preparation conditions. The effect of the average sizes of the Pt particles in the Pt/C catalysts obtained with this method on the electrocatalytical activity of the oxidation of methanol was investigated.
文摘The relationship of the electric conductivity of single and multi component of colloidal catalyst FeCl3 Al(i Bu)3 Phen with their concentration was studied in hydrogenated gasoline solvent at 25℃ ,meanwhile,the UV Vis spectra of the corresponding component of the catalyst were detected.The experimental results showed that Al(i Bu)3 existed in associated state and dissociated into ion couple.The reaction between Al(i Bu)3 and FeCl3 was the main reaction to form colloidal core.The Fe(III) on the surface of the colloidal particles was reduced to lower valence by Al(i Bu)3.The stable complex formed by the reaction between Phen and Fe(II) could prevent Fe(II) from being reduced to lower valence.The colloidal particles were comparatively stable by means of the electric double layer yielded by a proper excess of Al(i Bu)3.The stable colloidal particles could be formed in the optimal ratio of the catalyst components.
文摘The purpose of this work is the study the ability of the plant material Aloe vera to act as natural coagulant using raw water obtained from a drinking water treatment plant(Mila,Algeria).Different solvents such as:NaCl;NaOH and HCl were used as chemical activators to extract the active components from the Aloe vera plant,and different coagulation-flocculation experiments were conducted in a jar test apparatus to evaluate the perfor-mance of the extracted coagulant.Also,the effect of coagulant dose on some water parameters such as turbidity,pH,total alkalinity and organic matter were investigated.The results showed that the use of coagulants obtained by using different solvents increases the coagulation efficiency compared to the coagulant obtained from the raw material,for example the maximum turbidity removal efficiency was 28.23,78.07,83.46 and 85.15%when using powdered Aloe vera(raw material),AV-NaCl(0.5 M),AV-NaOH(0.05 M)and AV-HCl(0.05 M),respectively.The results defined,that the residual turbidity obtained in this work,where the Aloe vera was used(after treat-ment by solvents)produced a turbidity lower than the Algerian standard(5 NTU)with initial turbidity(13 NTU).In this study,the infrared spectrum study and analysis has revealed the presence of different functional groups,which are responsible for the coagulation process.
