Supported metal oxide nanoparticle electrocatalysts: How immobilization affects catalytic performance

Active and stable metal oxide nanoparticles supported on high surface area carriers (supports) play an important role in electrochemical energy conversion applications, for instance as anode electrocatalysts for the oxygen evolution reaction (OER) in water electrolyzers. While past studies most often focused on the activity and stability of the active oxide phase along with the surface area and durability of the support material of the combined catalyst/support couple, the influence of the immobilization method on its performance has been widely overlooked. Here, we emphasize the potential and limitations of the presented support methods and evaluate their applicability by means of controlling the metal loading, particle size and the accessibility of surface sites. Further, we present a technique applicable for tuning the loading of the metal oxide catalyst up to 20 wt. % avoiding agglomeration. We also establish a correlation between metal oxide loading and mass-based oxygen evolution activity.