Defect-density control of platinum-based nanoframes with high-index facets for enhanced electrochemical properties

Structure-engineered platinum-based nanoframes (NFs) at the atomic level can effectively improve the catalytic performance for fuel cells and other heterogeneous catalytic fields. We report herein, a microwave-assisted wet-chemical method for the preparation of platinum-copper-cobalt NFs with tunable defect density and architecture, which exhibit enhanced activity and durability towards the electro-oxidation reactions of methanol (MOR) and formic acid (FAOR). By altering the reduction/capping agents and thus the nucleation/growth kinetics, trimetallic platinum-copper-cobalt hexapod NFs with different density high-index facets are achieved. Especially, the rough hexapod nanoframes (rh-NFs) exhibit excellent specific activities towards MOR and FAOR, 7.25 and 5.20 times higher than those of benchmark Pt/C, respectively, along with prolonged durability. The excellent activities of the rh-NFs are assigned to a synergistic effect, including high density of defects and high-index facets, suitable d-band center, and open-framework structure. This synergistic working mechanism opens up a new way for enhancing their electrocatalytic performances by increasing defect density and high-index facets in open-framework platinum-based NFs.