ELECTROCHEMICAL ACTIVITY AND USE OF BIMETALLIC CATALYTIC STRUCTURES WITH DIFFERENT NI CONTENTS

This paper presents the results of a study of the effect of nickel particles on the properties of a bimetallic PtNi catalyst for membrane-electrode assemblies in hydrogen fuel cells. A series of samples with controlled Ni particles ranging in size from 6.0 to 15 nm were synthesized using magnetron sputtering with process time ranging from 30 to 120 s. It was found that fluxes obtained with sputtering times of 60−90 s (Ni particle size ranging from 6 to 8 nm) provide a balanced combination of differential characteristics: developed dendritic structure, active electrochemical surface area, catalytic activity and stability during stress testing. It is shown that deviations from the optimal synthesis parameters, either in the direction or by increasing the sputtering time, lead to degradation of either the catalytic activity or the stability of the system.