Solid-solution alloy nanoclusters of the immiscible gold-rhodium system achieved by a solid ligand-assisted approach for highly efficient catalysis

Striking effects are expected in solid-solution alloying, which offers enormous possibilities for various applications, especially in industrial catalysis. However, phase diagrams have revealed that a wide range of metallic elements are immiscible with each other even above their melting points. Achieving such unknown alloying between different immiscible metallic elements is highly desirable but challenging. Here, for the first time, by using an innovative solid ligand-assisted approach, we achieve the solid-solution alloying between the bulk-immiscible Au and Rh in plenty of clean, ultrafine (~ 1.6 nm) and highly dispersed nanoclusters. The solid-solution alloying of immiscible Au and Rh significantly enhances their catalytic performance toward the hydrogen evolution from formic acid in contrast to the monometallic Au and Rh nanoclusters. Moreover, the resultant binary solid-solution nanoclusters are stable without any segregation during catalytic reactions. The approach demonstrated here for homogeneously mixing the immiscible metals at the atomic scale will benefit the creation of advanced alloys and their catalytic applications in future.