Size Effects in Electrocatalysis of Fuel Cell Reactions on Supported Metal Nanoparticles

First Insight into Fluorinated Pt/Carbon Aerogels as More Corrosion-Resistant Electrocatalysts for Proton Exchange Membrane Fuel Cell Cathodes

“…10b) are in agreement with the TEM observations of the different catalysts. The reference material shows a single peak which is the fingerprint of a very well-dispersed catalyst [39,40], as evidenced in the representative TEM images of Fig. 9.…”

“…It is well known that ORR is a structure-sensitive reaction, and in that respect, platinum particle size plays a major role. The lower particle size presents a larger fraction of lowcoordinated sites on their surface which strongly adsorb ORR intermediates thus impacting negatively the activity [40,42]. It is therefore not surprising to obtain a higher specific activity in the case of the CA-supported electrocatalysts, owing to their larger Pt particles size [42].…”

Atomic-scale restructuring of hollow PtNi/C electrocatalysts during accelerated stress tests

“…A fivefold enhancement factor was found in single PEMFC test but shall be considered with caution. Indeed, kinetic measurements in solid electrolyte are associated with a number of limitations, which prevent correct determination of SA 0.90 : [61] (i) incomplete utilization of the catalyst, (ii) interference of the anode and the cathode (finite permeability of the Nafion ® membrane), and (iii) Ohmic and mass-transport losses (thus effectiveness factor below 1). Note however that the values of the apparent activation energy determined from least regressions at E = 0.90 V vs. RHE (22 and 24 kJ mol −1 for the solid Pt/C and the hollow PtNi/C electrocatalysts, respectively) agreed with those obtained by Damjanovic et al [62] (bulk Pt, E = 0.80 V vs. RHE, 25 kJ mol −1 ) and Paulus et al [63] (Pt/C, E = 0.90 V vs. RHE, 26 kJ mol −1 ).…”

Stability of carbon nanofibre-supported platinum catalysts in the presence of chloride under controlled mass-transfer conditions

“…Since the data were normalized with respect to surface Pt area, this implies that the specific electrocatalytic properties change during the dissolution. Changes like those in the figure may be due to the structure of the catalyst particles (development of steps, edges, and facets [30,31,32]), size effects [33,34,35], or the average distance between the catalyst particles [36] developing differently during the dissolution-redeposition process. (We attempted to take particle size effects explicitly into account in Fig.…”