The controllable growth of PtCuRh rhombic dodecahedral nanoframes as efficient catalysts for alcohol electrochemical oxidation

Abstract

Platinum-based catalysts with heterogeneous structures, such as three-dimensional (3D) nanoframes and highly branched architectures, have broad application prospects due to their fully accessible surfaces and high atom utilization. However, the fragile frames and dendrites with high energy easily suffer from structural collapse during catalytic processes. Hence, we synthesized Rh-strengthened PtCuRh rhombohedral dodecahedrons with nanodendrites (RDD) through a one-pot solvothermal method, which could be etched to obtain totally open nanoframe PtCuRh rhombohedral dodecahedrons with nanodendrites (RDND). More interestingly, the growth of the nanodendrites can be easily controlled through changing the reaction temperature. Meanwhile, the length of the nanodendrites can be controlled through adjusting the amount of CTAB and the reaction time. In addition, synergistic effects between Pt, Cu and Rh modified the electronic structure; in particular Rh metal oxide on the surface contributes heavily towards improving the electrocatalytic efficiency. Therefore the as-prepared catalyst PtCuRh RDND shows superior catalytic performance towards the methanol oxidation reaction (MOR) as well as the ethanol oxidation reaction (EOR) compared to TKK-commercial Pt/C. Remarkably, after 1000 electrochemical cycles of the MOR, the superior mass activity of PtCuRh RDND surpasses that of TKK-commercial Pt/C by 2.6 times, benefiting from enhanced CO tolerance and the stable structure. This work provides a facile and feasible strategy for synthesizing stable and efficient nanoframe catalysts.