Identical location TEM IL TEM procedures The TEM micrographs were

In the IL-TEM experiments, a suspension of 1 gPtM/C L−1 of PtM/C, composed of 5 wt% Nafion® solution (Aldrich) in 1:0.63 dry weight ratio, MQ-grade water and 20 wt% Pt3Co/C, was ultrasonically mixed for 30 min to obtain a well-dispersed ink. An aliquot of 5 μL was then deposited on a gold TEM grid and dried in air. The TEM grid baring the catalytic ink composed of PtM/C powder and Nafion® was used as the working electrode in the dry cell and kept in contact with the Nafion® 115 polymer electrolyte during the AST and the electrochemical characterizations (Fig.