Utilization of room temperature ionic liquids in the synthesis of Pt-based catalysts toward oxygen reduction reaction

Room temperature ionic liquids (RTILs) have been considered an interesting alternative to stabilizers in platinum (Pt) nanoparticle synthesis because they can prevent agglomeration of nanoparticles and act as a reaction medium. In addition, since RTILs remain in a liquid state over a wide range of temperatures, Pt catalyst processing steps, such as heat treatments and surface cleaning, can be omitted, and the Pt nanoparticles are uniformly dispersed under fuel cell operating conditions. Herein, we summarize the significant works on recent advances and developments using RTILs to prepare Pt-based catalysts related to the application in oxygen reduction reaction (ORR). Moreover, peculiar attention has been paid to the role of RTILs in improving the performance and efficiency of the RTILs and their effects on catalyst structure- and composition-control, detailed by examining several aspects. Finally, we outlook the challenges and opportunities of the research in the relevant fields for the development of ORR catalysts.