Control Over Morphological Characteristics of the Pt/C Catalysts Obtained by the Liquid-Phase Synthesis

One of the key components of low-temperature fuel cells with a proton-exchange membrane is an electrocatalyst contained in the porous electrodes. The most widespread synthesis methods are the liquid-phase ones that allow controlling the microstructure of the catalyst and, thus, its functional parameters. We have investigated the influence of various conditions of the liquid-phase synthesis on the morphological and electrochemical characteristics of the resulting platinum–carbon catalysts. An increase in the synthesis temperature has been established to allow for the narrowing of the size dispersion and the decrease in the average size of platinum nanoparticles. It has been found that the presence of a carbon support during the synthesis makes it possible to enhance the uniformity of the Pt NPs’ distribution over the surface of the support and decreasing the average particle size. As a result, the values of the active surface area grow almost 1.2–2 times compared to the homogeneous synthesis, during which the resulting colloid of platinum particles is deposited on the carbon support after the reduction. When using the molar ratio of hydroxyl groups/platinum in the range from 5 to 20 during the synthesis, the resulting Pt/C catalysts are characterized by an active surface area of more than 85 m²·g⁻¹_Pt. The possibility of scaling the synthesis method to obtain at least 1 g of the catalyst, which is not inferior in functional parameters to its commercial analog both before stress testing and after its completion, is also shown.