Electroless Pb Monolayer Deposition on Carbide and Nitrides for Energy Conversion Reactions

Fuel cells (FCs) and battery technologies are renewable options that may prevail in the vehicle industry, replacing fossil fuel dependence. This has led to the design and manufacture of electrocatalysts for energy conversion reactions in the mentioned technologies, such as the hydrogen oxidation reaction (HOR) and the oxygen reduction reaction (ORR). These reactions can be improved with new methods to obtain accessible, active and high-performance electrocatalysts. This study used a new Pb electroless (e-less) monolayer deposition approach to design electrocatalysts. This process is surface selective, surface controlled, and self-terminating, leading to a better design of active and accessible materials. We synthesized Pt/C, Pt/Au/C and Pt/NbN/C catalysts to catalyze the ORR in alkaline and acid mediums. We found that the e-less deposition approach placed a pseudo-monolayer (ML) of Pb on the selected supports (C, Au/C and NbN/C) and then Pt was placed on the support via spontaneous galvanic displacement (SGD) without the need of using an applied reduction potential. Our cyclic voltammograms results demonstrated the presence of hydrogen adsorption and desorption peaks associated to Pt on the C, Au/C and NbN/C supports. These materials were further tested for ORR generating oxygen polarization curves and the Pt/NbN/C provided half-wave potentials (E_1/2) vs. RHE of 750 mV in 0.1M HClO₄ and 810 mV in 0.1M KOH. Additional experiments will be held to characterize the placement of Pt on the supports using transmission electron microscopy (TEM) and addres the catalysts' performance by exposing them to numerous cyclic voltammogram cycles in both mediums.