Novel Fabrication and Characterization of a Bespoke Ultralow Loading Platinum Nanocluster on Carbon Black Catalyst

Magnetron sputtering offers a single-step, flexible, and environmentally friendly fabrication route to catalyst production, avoiding the requirement for complex syntheses or toxic chemicals normally required for more traditional wet chemical techniques. Using this facile method, a nanocluster platinum-on-carbon black catalyst is fabricated, rigorously characterized physically and electrochemically, and compared to a well-understood commercial catalyst (TKK). Scanning transmission electron microscopy (STEM) imaging reveals a mean cluster size of 1.1 ± 0.4 nm, half the commercial equivalent, with an associated electrochemically active surface area (ECSA) of 122.2 ± 9.6 m² g^-1, 40% higher than the commercial comparison. Catalytic performance is measured using the hydrogen evolution reaction (HER) and oxygen reduction reaction (ORR); results indicate a turnover frequency (TOF) 33 times higher than the commercial analogue in the HER and distinct kinetic differences between samples in the ORR. Rotating ring disc electrode voltammetry (RRDE) is utilized to study the mechanism further, and a discussion of activity vs size of particle is presented.