Pd-based catalysts exhibit higher catalytic activity and durability in many electrochemical reactions.However,the electrochemical performance can be further enhanced by fine-tune of the alloy composition.Although bina...Pd-based catalysts exhibit higher catalytic activity and durability in many electrochemical reactions.However,the electrochemical performance can be further enhanced by fine-tune of the alloy composition.Although binary alloys have been fully studied,the multicomponent alloys are far beyond understanding,which leaves cocktail effect a compromised explanation for the high-entropy alloy.Herein Pd nanosheet-seeded growth was used to synthesize a Pd-Zn-Cd ternary alloy by accurately controlling the Pd-Zn-Cd molar ratio through adjusting the amount of introduced Cd precursor.Through analysis of the crystal phase structure of PdCdZnx and PdZn_(x)Cd_(1-x),the competitive relationship of Zn and Cd in the alloying process with Pd was unveiled:Pd1Cd1 intermetallics(IMC)is thermodynamically favored over Pd_(1)Zn_(1)IMC in the ternary system.However,the increased structure stability of PdCd over PdZn does not bring about increased durability in the catalytic ethanol oxidation reaction.The morphology selection of Pd seeds is also crucial for the study,as Pd cubes,Pd tetrahedrons,and Pd octahedrons do not form PdZn in the same protocol.The successful alloying through the seeded growth depends on the maximum diffusion depth of foreign atoms into the seed.展开更多
Ultrathin Pd nanosheets(NSs)have great advantages in catalysis due to their large specific surface area and high percentage of under-coordinated atoms.However,the electrochemical performance still can be improved via ...Ultrathin Pd nanosheets(NSs)have great advantages in catalysis due to their large specific surface area and high percentage of under-coordinated atoms.However,the electrochemical performance still can be improved via composition-controllable growth of their solid solution.Herein,seeded alloying strategy was proposed to synthesize Pd-Cu solid solution from Pd NSs and Pd-Cu nanostructures with tunable molar ratios obtained by changing the amount of Cu precursor.As compared to the pristine Pd NSs,the Pd-Cu solid solution shows significantly enhanced methanol oxidation reaction(MOR)performance over those of Pd NSs and homemade Pd/C as the incorporation of Cu weakens the adsorption of CO intermediate on Pd in the MOR process.The choice of template is pivotal to the growth,as a shape-dependent behavior could be identified in the alloying of Cu with Pd nanosheets enclosed by{111}and{100}facets,Pd nanocubes enclosed by{100}facet,and Pd nano-tetrahedrons enclosed by{111}facet.The Pd-Cu solid solution with tunable composition can only be obtained from Pd NSs and the shape-dependent alloying process is mainly determined by the diffusion barrier and the minimum diffusion depth of the different facets.展开更多
基金the support of National Natural Science Foundation of China(No.22175127).
文摘Pd-based catalysts exhibit higher catalytic activity and durability in many electrochemical reactions.However,the electrochemical performance can be further enhanced by fine-tune of the alloy composition.Although binary alloys have been fully studied,the multicomponent alloys are far beyond understanding,which leaves cocktail effect a compromised explanation for the high-entropy alloy.Herein Pd nanosheet-seeded growth was used to synthesize a Pd-Zn-Cd ternary alloy by accurately controlling the Pd-Zn-Cd molar ratio through adjusting the amount of introduced Cd precursor.Through analysis of the crystal phase structure of PdCdZnx and PdZn_(x)Cd_(1-x),the competitive relationship of Zn and Cd in the alloying process with Pd was unveiled:Pd1Cd1 intermetallics(IMC)is thermodynamically favored over Pd_(1)Zn_(1)IMC in the ternary system.However,the increased structure stability of PdCd over PdZn does not bring about increased durability in the catalytic ethanol oxidation reaction.The morphology selection of Pd seeds is also crucial for the study,as Pd cubes,Pd tetrahedrons,and Pd octahedrons do not form PdZn in the same protocol.The successful alloying through the seeded growth depends on the maximum diffusion depth of foreign atoms into the seed.
基金This work was accomplished under the support of National Natural Science Foundation of Tianjin,China(No.22175127)Institute of Energy,Hefei Comprehensive National Science Center(No.19KZS207).
文摘Ultrathin Pd nanosheets(NSs)have great advantages in catalysis due to their large specific surface area and high percentage of under-coordinated atoms.However,the electrochemical performance still can be improved via composition-controllable growth of their solid solution.Herein,seeded alloying strategy was proposed to synthesize Pd-Cu solid solution from Pd NSs and Pd-Cu nanostructures with tunable molar ratios obtained by changing the amount of Cu precursor.As compared to the pristine Pd NSs,the Pd-Cu solid solution shows significantly enhanced methanol oxidation reaction(MOR)performance over those of Pd NSs and homemade Pd/C as the incorporation of Cu weakens the adsorption of CO intermediate on Pd in the MOR process.The choice of template is pivotal to the growth,as a shape-dependent behavior could be identified in the alloying of Cu with Pd nanosheets enclosed by{111}and{100}facets,Pd nanocubes enclosed by{100}facet,and Pd nano-tetrahedrons enclosed by{111}facet.The Pd-Cu solid solution with tunable composition can only be obtained from Pd NSs and the shape-dependent alloying process is mainly determined by the diffusion barrier and the minimum diffusion depth of the different facets.
