Insulin amyloid fibrils-templated rational self-assembly of vine-tree-like PtRh nanocatalysts for efficient methanol electrooxidation

Shape-controlled synthesis of platinum-based alloy nanocatalysts with well-designed size and structure is essential for developing highly efficient catalysts. Here, a biomolecule-based strategy for the synthesis of vine-tree-like PtRh nanowires (VT-PtRhNWs) using insulin amyloid fibrils (INSAFs) as sacrificial templates is presented. In this structure, the inner PtRh nanowires behave as the rigid 'tree' and the outer PtRh nanoparticles interconnects to form a spiral chain-like structure as the flexible 'vine'. Owning to the limitation effect of biological template, both of nanoparticles and nanowires present a very small size of less than 2 nm, and thus leading to a large electrochemical active surface area of 79.20m(2)/g. As a result, the as-prepared VT-PtRhNWs exhibit a much higher catalytic activity toward methanol oxidation compared with the commercial Pt/C catalyst, and also an improved CO tolerance, indicating a great potential as excellent electrocatalysts for fuel cells.