Encapsulating noble metal nanoparticles(NPs)within the zeolite framework enhances the stability and accessibility of active sites;however,direct synthesis remains a challenge because of the easy precipitation of noble...Encapsulating noble metal nanoparticles(NPs)within the zeolite framework enhances the stability and accessibility of active sites;however,direct synthesis remains a challenge because of the easy precipitation of noble metal species under strong alkali crystallization conditions.Herein,beta zeolite-encapsulated Pt NPs(Pt@Beta)were synthesized via a hydrothermal approach involving an unusual acid hydrolysis preaging step.The ligand—(3-mercaptopropyl)trimethoxysilane—and Pt precursor were cohydrolyzed and cocondensed with a silica source in an initially weak acidic environment to prevent colloidal precipitation by enhancing the interaction between the Pt and silica species.Thus,the resultant 0.2%Pt@Beta was highly active in the transformation of 5-hydroxymethylfurfural into 2,5-furandicarboxylic acid(FDCA)under atmospheric O2 conditions by using water as the solvent while stably evincing a high yield(90%)associated with a large turnover number of 176.The excellent catalysis behavior is attributable to the enhanced stability that inhibits Pt leaching and strengthens the intermediates that accelerate the rate-determining step for the oxidation of 5-formyl-2-furan carboxylic acid into FDCA.展开更多
Single nanoparticle(NP)collisions technique has been widely employed in electrocatalysis.However,the short collision duration of single NPs hinders the further improvement in their electrocatalytic performance.Here,to...Single nanoparticle(NP)collisions technique has been widely employed in electrocatalysis.However,the short collision duration of single NPs hinders the further improvement in their electrocatalytic performance.Here,to increase the dynamic collision duration of single NPs in the electron tunneling region,enhanced near-wall hindered diffusion is introduced in the stochastic collision process by coupling a Au ultramicroelectrode(UME)with a confined microchannel.In the case of single palladium nanoparticle(Pd NP)collisions for the hydrogen evolution reaction(HER),the hydrodynamic trapping confined in the microchannel effectively permits the activation of the HER on the single Pd NPs.The microchannel-based Au UME is promising in the application of single-NP collisions to energy conversion.展开更多
文摘Encapsulating noble metal nanoparticles(NPs)within the zeolite framework enhances the stability and accessibility of active sites;however,direct synthesis remains a challenge because of the easy precipitation of noble metal species under strong alkali crystallization conditions.Herein,beta zeolite-encapsulated Pt NPs(Pt@Beta)were synthesized via a hydrothermal approach involving an unusual acid hydrolysis preaging step.The ligand—(3-mercaptopropyl)trimethoxysilane—and Pt precursor were cohydrolyzed and cocondensed with a silica source in an initially weak acidic environment to prevent colloidal precipitation by enhancing the interaction between the Pt and silica species.Thus,the resultant 0.2%Pt@Beta was highly active in the transformation of 5-hydroxymethylfurfural into 2,5-furandicarboxylic acid(FDCA)under atmospheric O2 conditions by using water as the solvent while stably evincing a high yield(90%)associated with a large turnover number of 176.The excellent catalysis behavior is attributable to the enhanced stability that inhibits Pt leaching and strengthens the intermediates that accelerate the rate-determining step for the oxidation of 5-formyl-2-furan carboxylic acid into FDCA.
文摘Single nanoparticle(NP)collisions technique has been widely employed in electrocatalysis.However,the short collision duration of single NPs hinders the further improvement in their electrocatalytic performance.Here,to increase the dynamic collision duration of single NPs in the electron tunneling region,enhanced near-wall hindered diffusion is introduced in the stochastic collision process by coupling a Au ultramicroelectrode(UME)with a confined microchannel.In the case of single palladium nanoparticle(Pd NP)collisions for the hydrogen evolution reaction(HER),the hydrodynamic trapping confined in the microchannel effectively permits the activation of the HER on the single Pd NPs.The microchannel-based Au UME is promising in the application of single-NP collisions to energy conversion.
