ABSTRACT Two highly active and stable Pd-based intermetallic nanocrystals with early d-metals Pd3Ti and Pd3Zr have been developed. The nanocrystals are synthesized by co-reduction of the respective salts of Pd and Ti/Zr. Hard X-ray photoemission Spectroscopy (HAXPES) analysis of the nanocrystals indicates that the electronic properties of Pd are modified significantly, as evident from the lowering of the d-band center of Pd. The intermetallic nanocrystals dispersed in Vulcan carbon, Pd3Ti/C and Pd3Zr/C, exhibit improved electrocatalytic activity towards methanol and ethanol oxidation in an alkaline medium (0.5 M KOH), compared to those of commercially available catalysts such as Pd/C, Pt/C, and Pt3Sn/C. In addition, Pd3Ti/C and Pd3Zr/C show significantly higher activity towards the oxidation of formic acid in an acidic medium (0.5 M H2SO4), compared to those of Pd/C and Pt/C. The modification of the d-band center of Pd as a result of the alloying of Pd with the early d-metals Ti and Zr may be responsible for the enhanced catalytic activity.

中文翻译：

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用于在碱性和酸性介质中电氧化醇和甲酸的金属间 Pd3 X（X = Ti 和 Zr）纳米晶体

摘要 已经开发了两种高活性和稳定的 Pd 基金属间纳米晶体，其中包含早期的 d 金属 Pd3Ti 和 Pd3Zr。纳米晶体是通过共还原 Pd 和 Ti/Zr 的相应盐来合成的。纳米晶体的硬 X 射线光电发射光谱 (HAXPES) 分析表明，Pd 的电子特性显着改变，这从 Pd 的 d 带中心的降低中可以明显看出。与市售催化剂如 Pd/C、Pt/C 相比，分散在 Vulcan 碳、Pd3Ti/C 和 Pd3Zr/C 中的金属间纳米晶体在碱性介质（0.5 M KOH）中对甲醇和乙醇的氧化表现出更高的电催化活性。 C 和 Pt3Sn/C。此外，Pd3Ti/C 和 Pd3Zr/C 在酸性介质 (0.5 M H2SO4) 中对甲酸的氧化表现出显着更高的活性，与 Pd/C 和 Pt/C 相比。由于 Pd 与早期 d 金属 Ti 和 Zr 合金化，Pd 的 d 带中心的改性可能是提高催化活性的原因。