Control of chemical composition and incorporation of multiple metallic elements into a single metal nanoparticle(NP)in an alloyed or a phase-segregated state hold potential scientific merit;however,developing librarie...Control of chemical composition and incorporation of multiple metallic elements into a single metal nanoparticle(NP)in an alloyed or a phase-segregated state hold potential scientific merit;however,developing libraries of such structures using effective strategies is challenging owing to the thermodynamic immiscibility of repelling constituent metallic elements.Herein,we present a one-pot interfacial plasma-discharge-driven(IP-D)synthesis strategy for fabricating stable high-entropy-alloy(HEA)NPs exhibiting ultrasmall size on a porous support surface.Accordingly,an electric field was applied for 120 s to enhance the incorporation of multiple metallic elements(i.e.,CuAgFe,CuAgNi,and CuAgNiFe)into ally HEA-NPs.Further,NPs were attached to a porous magnesium oxide surface via rapid cooling.With solar light as the sole energy input,the CuAgNiFe catalyst was investigated as a reusable and sustainable material exhibiting excellent catalytic performance(100%conversion and 99% selectivity within1 min for a hydrogenation reaction)and consistent activity even after 20 cycles for a reduction reaction,considerably outperforming the majority of the conventional photocatalysts.Thus,the proposed strategy establishes a novel method for designing and synthesizing highly efficient and stable catalysts for the convertion of nitroarenes to anilines via chemical reduction.展开更多
Metal oxide-supported multielement alloy nanoparticles are very promising as highly efficient and cost-effective catalysts with a virtually unlimited compositional space.However,controllable synthesis of ultrasmall mu...Metal oxide-supported multielement alloy nanoparticles are very promising as highly efficient and cost-effective catalysts with a virtually unlimited compositional space.However,controllable synthesis of ultrasmall multielement alloy nanoparticles(us-MEA-NPs)supported on porous metal oxides with a homogeneous elemental distribution and good catalytic stability during long-term operation is extremely challenging due to their oxidation and strong immiscibility.As a proof of concept that such synthesis can be realized,this work presents a general“bottom-up”l ultrasonic-assisted,simultaneous electro-oxidation–reduction-precipitation strategy for alloying dissimilar elements into single NPs on a porous support.One characteristic of this technique is uniform mixing,which results from simultaneous rapid thermal decomposition and reduction and leads to multielement liquid droplet solidification without aggregation.This process was achieved through a synergistic combination of enhanced electrochemical and plasma-chemical phenomena at the metal–electrolyte interface(electron energy of 0.3–1.38 eV at a peak temperature of 3000 K reached within seconds at a rate of105 K per second)in an aqueous solution under an ultrasonic field(40 kHz).Illustrating the effectiveness of this approach,the CuAgNiFe-CoRuMn@MgO-P3000 catalyst exhibited exceptional catalytic efficiency in selective hydrogenation of nitro compounds,with over 99%chemoselectivity and nearly 100%conversion within 60 s and no decrease in catalytic activity even after 40 cycles(>98%conversion in 120 s).Our results provide an effective,transferable method for rationally designing supported MEA-NP catalysts at the atomic level and pave the way for a wide variety of catalytic reactions.展开更多
The synergistic effect of bi-component support catalysts via facile synthesis remains a pivotal challenge in catalysis,particularly under mild conditions.Therefore,this study reports an ultrasonication-plasma strategy...The synergistic effect of bi-component support catalysts via facile synthesis remains a pivotal challenge in catalysis,particularly under mild conditions.Therefore,this study reports an ultrasonication-plasma strategy to produce a PtGaPCoCoO@TiO_(x)site catalyst encapsulated within a high-entropy alloy framework.This approach harnesses instantaneous high-temperature plasma generated using an electrical field and ultrasonication under ambient conditions in H_(2)O.This study also elucidates the origin of the bifunctional effect in high-loading,ultra-stable,and ultra-fine PtGaPCoCoO catalysts,which are coated with a reducible TiO_(x)layer,thereby achieving optimal catalytic activity and hydrogen evolution reaction(HER)performance.PtGaPCo intimacy in PtGaPCoCoO@TiO_(x)is tuned and distributed on the porous titania coating based on strong metal-support interactions by leveraging the instantaneous high-energy input from plasma discharge and ultrasonication under ambient conditions in H_(2)O.PtGaPCoCoO@TiO_(x)exhibits remarkable selectivity and durability in the hydrogenation of 3-nitrophenylacetylene,even after 25 cycles with high conversion rates,significantly outperforming comparative catalysts lacking the ultrasonication plasma treatment and other reported catalysts.Furthermore,the catalyst exhibits exceptional HER activity,demonstrated by an overpotential of 187 mV at a current density of 10 mA cm^(-2)and a Tafel slope of 152 mV dec-1.This enhancement can be attributed to an increased electron density on the Pt surface within the PtGaPCo alloy.These findings highlight the potential of achieving synergistic chemical interactions among active metal sites in stable,industry-applicable catalysts.展开更多
High-entropy alloys(HEAs),which are near-equimolar alloys of four or more metal elements,have long been used to achieve the desired properties of catalytic materials.However,a novel alloying approach that includes mul...High-entropy alloys(HEAs),which are near-equimolar alloys of four or more metal elements,have long been used to achieve the desired properties of catalytic materials.However,a novel alloying approach that includes multiple principal elements at high concentrations to generate HEAs as novel catalytic materials has been reported.The fabrication of well-defined ultrastable supported HEAs,which provide superior performance and stability of catalysts owing to their augmented entropy and lower Gibbs free energy,remains a critical challenge.Supported HEA catalysts are sophisticated because of the variety of their morphologies and large sizes at the nanoscale.To address these challenges,PtPdInGaP@TiO2,comprising five different metals,is prepared via ultrasonic-assisted coincident electro-oxidation–reduction precipitation(U-SEO-P).The electronic structure and catalytic performance of HEA nanoparticles(NPs)are studied using hard scanning transmission electron microscopy(STEM),which is the first direct observation of the electronic structure of HEA NPs.This research takes an important step forward in fully describing individual HEA NPs.Combining STEM with deep learning with convolutional neural network(CNN)of selected individual HEA NPs reveals significant aspects of shape and size for widespread and commercially important PtPdInGaP@TiO2 NPs.The proposed method facilitates the detection and segmentation of HEA NPs,which has the potential for the development of high-performance catalysts for the reduction of organic compounds.展开更多
基金supported by the National Research Foundation (NRF)of South Korea (2022R1A2C1004392)。
文摘Control of chemical composition and incorporation of multiple metallic elements into a single metal nanoparticle(NP)in an alloyed or a phase-segregated state hold potential scientific merit;however,developing libraries of such structures using effective strategies is challenging owing to the thermodynamic immiscibility of repelling constituent metallic elements.Herein,we present a one-pot interfacial plasma-discharge-driven(IP-D)synthesis strategy for fabricating stable high-entropy-alloy(HEA)NPs exhibiting ultrasmall size on a porous support surface.Accordingly,an electric field was applied for 120 s to enhance the incorporation of multiple metallic elements(i.e.,CuAgFe,CuAgNi,and CuAgNiFe)into ally HEA-NPs.Further,NPs were attached to a porous magnesium oxide surface via rapid cooling.With solar light as the sole energy input,the CuAgNiFe catalyst was investigated as a reusable and sustainable material exhibiting excellent catalytic performance(100%conversion and 99% selectivity within1 min for a hydrogenation reaction)and consistent activity even after 20 cycles for a reduction reaction,considerably outperforming the majority of the conventional photocatalysts.Thus,the proposed strategy establishes a novel method for designing and synthesizing highly efficient and stable catalysts for the convertion of nitroarenes to anilines via chemical reduction.
基金National Research Foundation(NRF)funded by Republic of Korea,Grant/Award Number:NRF-2022R1A2C1004392Ministry of Science and ICT。
文摘Metal oxide-supported multielement alloy nanoparticles are very promising as highly efficient and cost-effective catalysts with a virtually unlimited compositional space.However,controllable synthesis of ultrasmall multielement alloy nanoparticles(us-MEA-NPs)supported on porous metal oxides with a homogeneous elemental distribution and good catalytic stability during long-term operation is extremely challenging due to their oxidation and strong immiscibility.As a proof of concept that such synthesis can be realized,this work presents a general“bottom-up”l ultrasonic-assisted,simultaneous electro-oxidation–reduction-precipitation strategy for alloying dissimilar elements into single NPs on a porous support.One characteristic of this technique is uniform mixing,which results from simultaneous rapid thermal decomposition and reduction and leads to multielement liquid droplet solidification without aggregation.This process was achieved through a synergistic combination of enhanced electrochemical and plasma-chemical phenomena at the metal–electrolyte interface(electron energy of 0.3–1.38 eV at a peak temperature of 3000 K reached within seconds at a rate of105 K per second)in an aqueous solution under an ultrasonic field(40 kHz).Illustrating the effectiveness of this approach,the CuAgNiFe-CoRuMn@MgO-P3000 catalyst exhibited exceptional catalytic efficiency in selective hydrogenation of nitro compounds,with over 99%chemoselectivity and nearly 100%conversion within 60 s and no decrease in catalytic activity even after 40 cycles(>98%conversion in 120 s).Our results provide an effective,transferable method for rationally designing supported MEA-NP catalysts at the atomic level and pave the way for a wide variety of catalytic reactions.
基金supported by two Mid-Level Researcher National Projects of the National Research Foundation(NRF)funded by the Ministry of Science and ICT,Republic of Korea(NRF-2022R1A2C1004392).
文摘The synergistic effect of bi-component support catalysts via facile synthesis remains a pivotal challenge in catalysis,particularly under mild conditions.Therefore,this study reports an ultrasonication-plasma strategy to produce a PtGaPCoCoO@TiO_(x)site catalyst encapsulated within a high-entropy alloy framework.This approach harnesses instantaneous high-temperature plasma generated using an electrical field and ultrasonication under ambient conditions in H_(2)O.This study also elucidates the origin of the bifunctional effect in high-loading,ultra-stable,and ultra-fine PtGaPCoCoO catalysts,which are coated with a reducible TiO_(x)layer,thereby achieving optimal catalytic activity and hydrogen evolution reaction(HER)performance.PtGaPCo intimacy in PtGaPCoCoO@TiO_(x)is tuned and distributed on the porous titania coating based on strong metal-support interactions by leveraging the instantaneous high-energy input from plasma discharge and ultrasonication under ambient conditions in H_(2)O.PtGaPCoCoO@TiO_(x)exhibits remarkable selectivity and durability in the hydrogenation of 3-nitrophenylacetylene,even after 25 cycles with high conversion rates,significantly outperforming comparative catalysts lacking the ultrasonication plasma treatment and other reported catalysts.Furthermore,the catalyst exhibits exceptional HER activity,demonstrated by an overpotential of 187 mV at a current density of 10 mA cm^(-2)and a Tafel slope of 152 mV dec-1.This enhancement can be attributed to an increased electron density on the Pt surface within the PtGaPCo alloy.These findings highlight the potential of achieving synergistic chemical interactions among active metal sites in stable,industry-applicable catalysts.
基金supported by the National Research Foundation of the Republic Korea(NRF-2022R1A2C1004392)NRF funded by the Ministry of Education(IRISRS 2023-00240109).This work was supported by 2024.
文摘High-entropy alloys(HEAs),which are near-equimolar alloys of four or more metal elements,have long been used to achieve the desired properties of catalytic materials.However,a novel alloying approach that includes multiple principal elements at high concentrations to generate HEAs as novel catalytic materials has been reported.The fabrication of well-defined ultrastable supported HEAs,which provide superior performance and stability of catalysts owing to their augmented entropy and lower Gibbs free energy,remains a critical challenge.Supported HEA catalysts are sophisticated because of the variety of their morphologies and large sizes at the nanoscale.To address these challenges,PtPdInGaP@TiO2,comprising five different metals,is prepared via ultrasonic-assisted coincident electro-oxidation–reduction precipitation(U-SEO-P).The electronic structure and catalytic performance of HEA nanoparticles(NPs)are studied using hard scanning transmission electron microscopy(STEM),which is the first direct observation of the electronic structure of HEA NPs.This research takes an important step forward in fully describing individual HEA NPs.Combining STEM with deep learning with convolutional neural network(CNN)of selected individual HEA NPs reveals significant aspects of shape and size for widespread and commercially important PtPdInGaP@TiO2 NPs.The proposed method facilitates the detection and segmentation of HEA NPs,which has the potential for the development of high-performance catalysts for the reduction of organic compounds.
