Metal nanoparticles entrapped in metal matrices.

We developed synthetic methods for the doping of metals (M) with metallic nanoparticles (NPs). To the best of our knowledge – unlike oxides, polymers and carbon-based supports – metals were not used so far as supporting matrices for metallic NPs. The composites (denoted M1-NPs@M2) comprise two separate phases: the metallic NPs (the dopant) and the entrapping 3D porous metallic matrix, within which the NPs are intimately held and well dispersed. Two different general synthetic strategies were developed, each resulting in a group of materials with characteristic structure and properties. The first strategy uses pre-prepared NPs and these are entrapped during reductive formation of the metallic matrix from its cation. The second strategy is in situ growth of the doped metallic NPs within the pre-prepared entrapping metallic matrix. These two methods were developed for two types of entrapping metallic matrices with different morphologies: porous aggregated metallic matrices and metallic foams. The leading case in this study was the use of Pt as the NP dopant and Ag as the entrapping matrix, using all of the four combinations – entrapment or growth within aggregated Ag or Ag foam matrices. Full physical and chemical properties analysis of these novel types of materials was carried out, using a wide variety of analytical methods. The generality of the methods developed for these bi-metallic composites was investigated and demonstrated on additional metallic pairs: Au NPs within Ag matrices, Pd NPs within Ni matrices and Ir-NPs within a Rh matrix. As the main application of metallic NPs is in catalysis, the catalytic activity of M1-NPs@M2 is demonstrated successfully for entrapped Pt within Ag for reductive catalytic reactions, and for Pd within Ni for the electrocatalytic hydrogen oxidation reaction. Metallic nanoparticles have been traditionally dispersed on ceramics and carbons, but never on porous metals. Methods for the preparation of such materials are described, and catalysis is demonstrated for reductions and for H2 electro-oxidation.

我们开发了与金属纳米颗粒（NPS）掺杂金属（M）的合成方法。 ，其中NP被密切持有并分散开发了一般的合成策略，每种策略都具有特征性的结构和性能。第一个策略使用预先准备的NP，并且在阳离子中减少了金属基质的形成。 Porous aggregated metallic materies and metallic foams. The leading case in this study was the use of Pt as the NP dopant and Ag as the entrance matrix, using all of the four combinations – entrapment or growth within aggregated Ag or Ag foam materies. Full physical and chemical properties analysis of these novel types of materials was carried out, using a wide variety of analytical methods. The generality of the methods developed for these bi-metallic compositions was在其他金属对上进行了研究和证明：AG材料中的AU NP，Ni材料中的PD NP和RH基质中的IR-NPs。 传统上，金属纳米颗粒分散在陶瓷和碳上，但从未描述过用于制备此类材料的方法，并证明了催化作用以减少和H2电氧化。