Herein,a series of manganese oxide catalysts with different valences(Mn_(3)O_(4),Mn_(2)O_(3),and MnO_(2))were designed and synthesized for the synthesis of ethylene urea(EU)from ethylenediamine(EDA)and carbon dioxide(...Herein,a series of manganese oxide catalysts with different valences(Mn_(3)O_(4),Mn_(2)O_(3),and MnO_(2))were designed and synthesized for the synthesis of ethylene urea(EU)from ethylenediamine(EDA)and carbon dioxide(CO_(2)).With a maximal EDA conversion of 82%and EU selectivity of 99%at 160℃ for 2 h,Mn_(2)O_(3) catalysts had the best catalytic activity among them,which was superior to the reported catalysts.In the following order:Mn_(2)O_(3)>MnO_(2)>Mn_(3)O_(4),the catalytic activity for the synthesis of EU from CO_(2) and EDA decreased.Further characterization showed the Mn_(2)O_(3) catalyst possessed a greater Mn^(3+)/Mn4+ratio and more surface oxygen vacancies than the MnO_(2) and Mn_(3)O_(4),which improved its capacity to adsorb and activate CO_(2) and EDA.After four recycling runs,the EDA conversion slightly declined from 82%to 56%on Mn_(2)O_(3) catalyst,while no obvious change in EU selectivity was observed.The loss of surface Ov contents and Mn^(3+)proportion were concluded as main reasons for the decrease in catalytic activity over Mn_(2)O_(3) catalyst.This work demonstrated a metal oxide catalyst that was efficient in producing EU from CO_(2) and EDA.展开更多
As a transition material between bulk materials and individual atoms,nickel clusters have interesting electrical and structural characteristics that could make them useful as catalysts.To examine the catalytic efficie...As a transition material between bulk materials and individual atoms,nickel clusters have interesting electrical and structural characteristics that could make them useful as catalysts.To examine the catalytic efficiency of nickel clusters in different applications,this Review combines experimental techniques with density functional theory(DFT).Researchers have shown that nickel clusters can activate and alter tiny molecules like CO,NO,and H_(2)through DFT studies that delve deeply into their electronic structures,adsorption mechanisms,and stability.These findings lay the groundwork for the development of effective catalysts for various processes.Nickel clusters considerably improve the hydrogen evolution reaction(HER),indicating their promise for renewable energy conversion.Furthermore,electrocatalysis for the oxygen evolution reaction(OER)showcases the electrochemical performance of nickel clusters,demonstrating their stability and efficiency.The adaptability of nickel clusters is further demonstrated by their use in nitrogen reduction to ammonia.Experimental data confirm that these clusters are good catalysts for this crucial industrial activity.Hydrocarbon reforming and pollutant degradation are two areas in which research has shown that nickel clusters can be useful in thermal reactions.X-ray absorption spectroscopy(XAS)and environmental transmission electron microscopy(ETEM)are examples of in situ characterization techniques that support theoretical predictions by providing real-time insights into the structural alterations and active sites of nickel clusters during these processes.Preparing the way for future research and practical applications in energy and environmental technologies,this thorough study highlights the great potential of nickel clusters in constructing sustainable and efficient catalytic systems.展开更多
The two-dimensional layered double hydroxides(LDHs)and zero-dimensional metal clusters have emerged as promising nanomaterials in the field of sustainable water oxidation,which can also facilitate joint experimental a...The two-dimensional layered double hydroxides(LDHs)and zero-dimensional metal clusters have emerged as promising nanomaterials in the field of sustainable water oxidation,which can also facilitate joint experimental and computational studies.In this study,the synthesis of Ni_(6)@LDH composites,comprising atomically precise Ni_(6)(MPA)12(MPA:mercaptopropionic acid)clusters embedded into LDH nanosheets via electrostatic interaction,represents a significant advancement in the development of nanomaterials for sustainable water oxidation.Ni_(6)@NiFe-LDH exhibits superior electrochemical performance in oxygen evolution reaction(OER),exhibiting OER overpotentials of 198 mV@10 mA·cm^(-2) and 290 mV@100 mA·cm^(-2) with a low Tafel slope of 29 mV·dec^(-1).It surpasses the corresponding NiFe-LDH and commercial RuO_(2) catalysts,primarily due to the synergistic interaction between Ni_(6) clusters and LDHs.Interestingly,our combined experimental and computational approach reveals that the M-OOH_(ads )formation is the rate-determining step(RDS)for the Ni_(6)-based catalysts,differing from the RDS for NiFe-LDH itself(the M-Oads formation).These efforts serve as an attempt to push forward the current research frontier to study structure–property relationships progressing from the micro-/nano-level to the precise atomic-level.展开更多
基金supported by the National Natural Science Foundation of China(No.22278041)the Foundation of State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering(No.2022-K78)+1 种基金Jiangsu Province Key Laboratory of Fine Petrochemical Engineering(No.KF2107)the Advanced Catalysis and Green Manufacturing Collab-orative Innovation Center(No.ACGM2022-10-07)。
文摘Herein,a series of manganese oxide catalysts with different valences(Mn_(3)O_(4),Mn_(2)O_(3),and MnO_(2))were designed and synthesized for the synthesis of ethylene urea(EU)from ethylenediamine(EDA)and carbon dioxide(CO_(2)).With a maximal EDA conversion of 82%and EU selectivity of 99%at 160℃ for 2 h,Mn_(2)O_(3) catalysts had the best catalytic activity among them,which was superior to the reported catalysts.In the following order:Mn_(2)O_(3)>MnO_(2)>Mn_(3)O_(4),the catalytic activity for the synthesis of EU from CO_(2) and EDA decreased.Further characterization showed the Mn_(2)O_(3) catalyst possessed a greater Mn^(3+)/Mn4+ratio and more surface oxygen vacancies than the MnO_(2) and Mn_(3)O_(4),which improved its capacity to adsorb and activate CO_(2) and EDA.After four recycling runs,the EDA conversion slightly declined from 82%to 56%on Mn_(2)O_(3) catalyst,while no obvious change in EU selectivity was observed.The loss of surface Ov contents and Mn^(3+)proportion were concluded as main reasons for the decrease in catalytic activity over Mn_(2)O_(3) catalyst.This work demonstrated a metal oxide catalyst that was efficient in producing EU from CO_(2) and EDA.
基金National Natural Science Foundation of China(22172167)Open fund of State Key Laboratory of Catalysis(DICP,2024SKL-A-006).
文摘As a transition material between bulk materials and individual atoms,nickel clusters have interesting electrical and structural characteristics that could make them useful as catalysts.To examine the catalytic efficiency of nickel clusters in different applications,this Review combines experimental techniques with density functional theory(DFT).Researchers have shown that nickel clusters can activate and alter tiny molecules like CO,NO,and H_(2)through DFT studies that delve deeply into their electronic structures,adsorption mechanisms,and stability.These findings lay the groundwork for the development of effective catalysts for various processes.Nickel clusters considerably improve the hydrogen evolution reaction(HER),indicating their promise for renewable energy conversion.Furthermore,electrocatalysis for the oxygen evolution reaction(OER)showcases the electrochemical performance of nickel clusters,demonstrating their stability and efficiency.The adaptability of nickel clusters is further demonstrated by their use in nitrogen reduction to ammonia.Experimental data confirm that these clusters are good catalysts for this crucial industrial activity.Hydrocarbon reforming and pollutant degradation are two areas in which research has shown that nickel clusters can be useful in thermal reactions.X-ray absorption spectroscopy(XAS)and environmental transmission electron microscopy(ETEM)are examples of in situ characterization techniques that support theoretical predictions by providing real-time insights into the structural alterations and active sites of nickel clusters during these processes.Preparing the way for future research and practical applications in energy and environmental technologies,this thorough study highlights the great potential of nickel clusters in constructing sustainable and efficient catalytic systems.
基金Natural Science Foundation of China(No.22172167).
文摘The two-dimensional layered double hydroxides(LDHs)and zero-dimensional metal clusters have emerged as promising nanomaterials in the field of sustainable water oxidation,which can also facilitate joint experimental and computational studies.In this study,the synthesis of Ni_(6)@LDH composites,comprising atomically precise Ni_(6)(MPA)12(MPA:mercaptopropionic acid)clusters embedded into LDH nanosheets via electrostatic interaction,represents a significant advancement in the development of nanomaterials for sustainable water oxidation.Ni_(6)@NiFe-LDH exhibits superior electrochemical performance in oxygen evolution reaction(OER),exhibiting OER overpotentials of 198 mV@10 mA·cm^(-2) and 290 mV@100 mA·cm^(-2) with a low Tafel slope of 29 mV·dec^(-1).It surpasses the corresponding NiFe-LDH and commercial RuO_(2) catalysts,primarily due to the synergistic interaction between Ni_(6) clusters and LDHs.Interestingly,our combined experimental and computational approach reveals that the M-OOH_(ads )formation is the rate-determining step(RDS)for the Ni_(6)-based catalysts,differing from the RDS for NiFe-LDH itself(the M-Oads formation).These efforts serve as an attempt to push forward the current research frontier to study structure–property relationships progressing from the micro-/nano-level to the precise atomic-level.
