La-Co alloy nanowires can be made in pulse reversal current(PRC) and direct current(DC) electrodepositions under nonaqueous system, with the porous anodic aluminum oxide(AAO) as template. This membrane is subject to t...La-Co alloy nanowires can be made in pulse reversal current(PRC) and direct current(DC) electrodepositions under nonaqueous system, with the porous anodic aluminum oxide(AAO) as template. This membrane is subject to the dual-oxidation (two-step) anodizing. Scanning electron microscope(SEM) examination shows that all of the nanowires have uniform diameter about 200 nm, and their diameters are determined by the pore diameter of applied AAO template. X-ray energy dispersion analysis indicates that the chemical composition of La and Co elements is very close to 1-2 in stoichiometry. X-ray diffraction pattern investigation demonstrates that La-Co nanowire is the face-centered cubic(FCC) LaCo13.展开更多
Highly active and durable electrocatalysts towards oxygen reduction reaction(ORR)are imperative for the commercialization application of proton exchange membrane fuel cells.By manipulating ligand effect,structural con...Highly active and durable electrocatalysts towards oxygen reduction reaction(ORR)are imperative for the commercialization application of proton exchange membrane fuel cells.By manipulating ligand effect,structural control,and strain effect,we report here the precise preparation of Mo-doped Pt_(3)Co alloy nanowires(Pt_(3)Co-Mo NWs)as the efficient catalyst towards ORR with high specific activity(0.596 mA cm^(−2))and mass activity(MA,0.84 A mg^(−1)_(Pt)),much higher than those of undoped counterparts.Besides activity,Pt_(3)Co-Mo NWs also demonstrate excellent structural stability and cyclic durability even after 50,000 cycles,again surpassing control samples without Mo dopants.According to the strain maps and DFT calculations,Mo dopants could modify the electronic structure of both Pt and Co to achieve not only optimized oxygen-intermediate binding energy on the interface but also increased the vacancy formation energy of Co,together leading to enhanced activity and durability.This work provides not only a facile methodology but also an in-depth investigation of the relationship between structure and properties to provide general guidance for future design and optimization.展开更多
基金Project(04011311) supported by the Natural Science Foundation of Guangdong Province, ChinaProject(2006B14001001) supported by the Science and Technology Plan of Guangdong Province, ChinaProject(50471108) supported by the National Natural Science Foundation of China
文摘La-Co alloy nanowires can be made in pulse reversal current(PRC) and direct current(DC) electrodepositions under nonaqueous system, with the porous anodic aluminum oxide(AAO) as template. This membrane is subject to the dual-oxidation (two-step) anodizing. Scanning electron microscope(SEM) examination shows that all of the nanowires have uniform diameter about 200 nm, and their diameters are determined by the pore diameter of applied AAO template. X-ray energy dispersion analysis indicates that the chemical composition of La and Co elements is very close to 1-2 in stoichiometry. X-ray diffraction pattern investigation demonstrates that La-Co nanowire is the face-centered cubic(FCC) LaCo13.
基金financially supported by the Natural Sciences and Engineering Research Council of Canada(NSERC),through the Discovery Grant Program(RGPIN-2018-06725RGPIN-201705080)+2 种基金the Discovery Accelerator Supplement Grant program(RGPAS-2018-522651)by the New Frontiers in Research Fund-Exploration program(NFRFE-2019-00488)support from the University of Alberta and Future Energy Systems(FES)。
文摘Highly active and durable electrocatalysts towards oxygen reduction reaction(ORR)are imperative for the commercialization application of proton exchange membrane fuel cells.By manipulating ligand effect,structural control,and strain effect,we report here the precise preparation of Mo-doped Pt_(3)Co alloy nanowires(Pt_(3)Co-Mo NWs)as the efficient catalyst towards ORR with high specific activity(0.596 mA cm^(−2))and mass activity(MA,0.84 A mg^(−1)_(Pt)),much higher than those of undoped counterparts.Besides activity,Pt_(3)Co-Mo NWs also demonstrate excellent structural stability and cyclic durability even after 50,000 cycles,again surpassing control samples without Mo dopants.According to the strain maps and DFT calculations,Mo dopants could modify the electronic structure of both Pt and Co to achieve not only optimized oxygen-intermediate binding energy on the interface but also increased the vacancy formation energy of Co,together leading to enhanced activity and durability.This work provides not only a facile methodology but also an in-depth investigation of the relationship between structure and properties to provide general guidance for future design and optimization.
