Synthesis of PtCu–based nanocatalysts: Fundamentals and emerging challenges in energy conversion

Proton exchange membrane fuel cell and direct methanol fuel cells have gained more attention due to high–energy density, remarkable conversion efficiency, and low emission. However, their widely practical application was hindered by the high usage, limited sources, and high price of Pt catalysts. To achieve more cost–effective catalytic systems, PtCu–based multi–metallic nanoparticles are highly efficient for the oxygen reduction reaction (ORR) and methanol oxidation reaction (MOR). The incorporation of non–noble Cu metal can alter the properties of hybrids by forming new facets, planes, edges to promote the cleavage or formation of chemical bonds in catalytic reaction. This is a rapid growing area with numerous contributions from the interdisciplinary areas of nanocatalysis. This paper has summarized the recent progress in the past two years, in synthesizing PtCu–based alloys with various composition and morphologies, and critically discussed the effect of the catalyst preparation method, metal precursor, surfactant, reductant and heating temperature on nanostructure and electronic configuration. The important role of the composition, size, and morphology of PtCu bimetallic catalysts for electro oxidation reactions has been further established for structure–dependency studies. The challenges and perspectives of nanocatalysts for ORR and MOR discussed in this work is to provide further insights into rational design for cost–effective materials for energy.