Atomic-scaled surface engineering Ni-Pt nanoalloys towards enhanced catalytic efficiency for methanol oxidation reaction

Surface engineering is known as an effective strategy to enhance the catalytic properties of Pt-based nanomaterials.Herein,we report on surface engineering Ni-Pt nanoalloys with a facile method by varying the Ni doping concentration and oleylamine/oleicacid surfactant-mix.The alloy-composition,exposed facet condition,and surface lattice strain are,thereby manipulated to optimize the catalytic efficiency of such nanoalloys for methanol oxidation reaction(MOR).Exemplary nanoalloys including Ni_(0.69)Pt_(0.31)truncated octahedrons,Ni_(0.45)Pt_(0.55)nanomultipods and Ni_(0.20)Pt_(0.80)nanoflowers are thoroughly characterized,with a commercial Pt/C catalyst as a common benchmark.Their variations in MOR catalytic efficiency are significant:2.2 A/mgPt for Ni_(0.20)Pt_(0.80)nanoflowers,1.2 A/mgPt for Ni_(0.45)Pt_(0.55)nanomultipods,0.7 A/mgPt for Ni_(0.69)Pt_(0.31)truncated octahedrons,and 0.6 A/mgPt for the commercial Pt/C catalysts.Assisted by density functional theory calculations,we correlate these observed catalysis-variations particularly to the intriguing presence of surface interplanar-strains,such as{111}facets with an interplanar-tensile-strain of 2.6%and{200}facets with an interplanar-tensile-strain of 3.5%,on the Ni_(0.20)Pt_(0.80)nanoflowers.

Fe3O4 Octahedral Colloidal Crystals

我们在场为没有底层的帮助的高度命令的八面的 Fe3O4 胶体的单个晶体的大规模制造的一个灵巧、可控制的方法。油的酸被用来在胶体的答案减少 nano 大楼块的溶解度并且导致一个结晶化过程。我们的胶体的晶体具有 multimicron 尺寸并且显示出典型结晶的特征。他们有很柔韧的结构并且当一篇小说与相对狭窄的毛孔尺寸分布订了磁性的 mesoporous 材料，能服务。样品基于它的好 crystallinity，以及 interparticle 在 5 K 拥有 100 K 的极其高的 Verwey 转变温度(T V ) 和 86 emu/g 的高浸透磁化(M S ) 偶极的相互作用行为从它的唯一的结构产生。电气化学的大小表明了 mesoporous 的优秀能力胶体的晶体当在锂离子电池使用了时。