<p>The study evaluates the performance of binder-free Pt-based catalysts for oxygen reduction reaction (ORR) using cavity microelectrode (CME) techniques. The use of binders during the deposition of an electrocatalyst on conducting support can adversely affect the mass transport properties, including the diffusion of reactants and products, to and from the catalyst surface. To mitigate these effects, pristine catalysts are employed, avoiding any performance loss. By employing CME, pristine powder catalysts were evaluated without the need of binders, demonstrating superior activity compared to Nafion^®-coated variants, which suffer from active site blockage. The commercial Pt/C catalyst and the emerging 2D Pt/Ti₃C₂T_x catalyst have been utilized to showcase these effects in ORR electrocatalysis. Notably, Pt/Ti₃C₂T_x showed superior ORR activity than Pt/C in both systems, which is attributed to the strong metal support interaction (SMSI) in the catalyst. This interaction has been experimentally confirmed via X-ray Photoelectron Spectroscopy (XPS) and Ultraviolet Photoelectron Spectroscopy (UPS), demonstrating a downshift in the Pt d-band center for Pt/Ti₃C₂T_x. The superior performance of the catalyst and the enhanced catalytic activity via CME technique are attributed to the downshift of the d-band center and the exclusion of binders, respectively.</p>