Surface strain engineering is considered as an effective strategy to promote the electrocatalytic properties of noble metal nanocrystals.Herein,we construct a dual-phase palladium-copper(DP-PdCu)bimetallic electrocata...Surface strain engineering is considered as an effective strategy to promote the electrocatalytic properties of noble metal nanocrystals.Herein,we construct a dual-phase palladium-copper(DP-PdCu)bimetallic electrocatalyst with remarkable biaxial strain via a one-pot wet-chemical approach for formic acid oxidation.The biaxial strain originates from the lattice mismatch between the disordered face-centered cubic(FCC)phase and ordered body-centered cubic(BCC)phase in each of DP-PdCu:nanoparticles.The proportion of FCC and BCC phases and size of PdCu nanoparticles are dependent on the addition amount of:capping agent,cetyltrimethylammonium bromide(CTAB).Density functional theory calculations reveal the downshift of d-band:center of Pd atoms due to the interfacial strain,which weakens the adsorption strength of undesired intermediates.These merit the,DP-PdCu catalyst with superior mass activity of 0.55 A·mg_(pd)^(-1) and specific activity of 1.91 mA·cm_(pd)^(-2) toward formic acid oxidation,outperforming the single FCC/EICC PdCu and commercial Pd/C catalysts.This will provide new insights into the structure design of high-performance electrocatalysts via strain engineering.展开更多
Nano-particle Pd/?-Al2O3 monometallic and Pd-Cu/?-Al2O3 bimetall ic catalysts were prepared by solvated metal atom impregnation (SMAI) method. Th e results of XRD measurement indicated that Pd- Cu alloy was formed in ...Nano-particle Pd/?-Al2O3 monometallic and Pd-Cu/?-Al2O3 bimetall ic catalysts were prepared by solvated metal atom impregnation (SMAI) method. Th e results of XRD measurement indicated that Pd- Cu alloy was formed in the bim etallic catalysts and the crystalline particle size of the alloy increased as Cu contents increased with average diameters < 6.0nm for all the samples. XPS and Auger spectra showed that Pd was in zero- valent state, Cu existed mainly in z ero- valent state and partially in monovalent state Cu+. The Pd/?-Al2O3 and Pd-Cu/?-Al2O3 catalysts exhibited higher activity for CO oxidation at low temperature. The activity of Pd-Cu/?-Al2O3 bimetallic catalyst was hig her than that of Pd/?-Al2O3 monometallic catalyst. The Pd-Cu/?-Al2O3 c atalyst with Pd/Cu atomic ratio of 1∶1 showed the highest activity.展开更多
基金supported by the National Key Research and Development Program of China(No.2016YFB0101201)the National Natural Science Foundation of China(Nos.21822506 and 51761165025)the 111 project of B12015.
文摘Surface strain engineering is considered as an effective strategy to promote the electrocatalytic properties of noble metal nanocrystals.Herein,we construct a dual-phase palladium-copper(DP-PdCu)bimetallic electrocatalyst with remarkable biaxial strain via a one-pot wet-chemical approach for formic acid oxidation.The biaxial strain originates from the lattice mismatch between the disordered face-centered cubic(FCC)phase and ordered body-centered cubic(BCC)phase in each of DP-PdCu:nanoparticles.The proportion of FCC and BCC phases and size of PdCu nanoparticles are dependent on the addition amount of:capping agent,cetyltrimethylammonium bromide(CTAB).Density functional theory calculations reveal the downshift of d-band:center of Pd atoms due to the interfacial strain,which weakens the adsorption strength of undesired intermediates.These merit the,DP-PdCu catalyst with superior mass activity of 0.55 A·mg_(pd)^(-1) and specific activity of 1.91 mA·cm_(pd)^(-2) toward formic acid oxidation,outperforming the single FCC/EICC PdCu and commercial Pd/C catalysts.This will provide new insights into the structure design of high-performance electrocatalysts via strain engineering.
文摘Nano-particle Pd/?-Al2O3 monometallic and Pd-Cu/?-Al2O3 bimetall ic catalysts were prepared by solvated metal atom impregnation (SMAI) method. Th e results of XRD measurement indicated that Pd- Cu alloy was formed in the bim etallic catalysts and the crystalline particle size of the alloy increased as Cu contents increased with average diameters < 6.0nm for all the samples. XPS and Auger spectra showed that Pd was in zero- valent state, Cu existed mainly in z ero- valent state and partially in monovalent state Cu+. The Pd/?-Al2O3 and Pd-Cu/?-Al2O3 catalysts exhibited higher activity for CO oxidation at low temperature. The activity of Pd-Cu/?-Al2O3 bimetallic catalyst was hig her than that of Pd/?-Al2O3 monometallic catalyst. The Pd-Cu/?-Al2O3 c atalyst with Pd/Cu atomic ratio of 1∶1 showed the highest activity.