Superior Metal–Support Interactions in Reliable Pt Catalysts for Carbon-Free Proton Exchange Membrane Fuel Cell Cathodes

This study explored the enhancement of TiO₂ support materials in proton exchange membrane fuel cells (PEMFCs) through Nb and Si codoping, intending to achieve breakthrough electrocatalytic performance while avoiding carbon corrosion vulnerabilities. Nb, Si co-doped TiO₂ (NSTO) was engineered to improve the physicochemical properties and electrocatalytic effectiveness, surpassing Nb-doped TiO₂ (NTO) and carbon-infused systems. Silicon doping modifies the electronic band structure and enhances the surface chemistry, significantly improving the strong metal–support interaction and oxygen vacancy concentration, resulting in enhanced electrical conductivity and robust stability of NSTO. This leads to strengthened interaction with platinum and enhanced oxygen reduction reaction performance. Initial evaluations show that NSTO provides superior durability and catalytic efficiency compared to commercial Pt/C without the risks associated with carbon corrosion. Results of single-stack cell tests under various conditions demonstrate promising performance without degradation of the electrochemical activity after 10,000 accelerated degradation testing (ADT) cycles in half-cell tests and in single-stack cell tests after 5,000 ADT cycles. Our research substantiates the potential of NSTO as a superior support material for PEMFCs, paving the way for sustainable advancements in fuel cell technologies.