A Study on In-Pore Anchoring-Driven Growth of Pt Nanoparticles in Cylindrical Mesoporous Carbon for Electrocatalytic Applications

Abstract

Platinum (Pt)-based electrocatalysts exhibit excellent catalytic activity but suffer from limited durability due to nanoparticle migration, agglomeration, and dissolution during operation. In this study, we propose an in-pore anchoring and growth strategy to stabilize Pt nanoparticles within cylindrical mesoporous carbon. Pt precursors are selectively immobilized inside mesopores through amine- mediated interactions and subsequently confined during carbonization. The synthesis employs sucrose as a carbon precursor and NaOH-based silica template removal, providing a safer and more environmentally benign route compared to conventional organic-solvent- or HF-assisted processes. The resulting Pt30-CYL catalyst features an ordered cylindrical mesoporous structure with uniformly dispersed Pt nanoparticles, leading to enhanced structural stability relative to a commercial Pt/C catalyst. Electrochemical hydrogen evolution reaction (HER) measurements demonstrate that Pt30-CYL delivers superior performance at high current densities with lower overpotentials and exhibits minimal performance variation during 71 h of continuous operation at −0.24 V vs. RHE. In contrast, while the commercial Pt/C catalyst maintains a similar overpotential at −10 mA cm⁻², it shows a more pronounced increase in polarization at higher current densities. These results indicate that the combination of structural confinement and amine-based chemical anchoring effectively suppresses Pt migration, agglomeration, and dissolution. This work establishes a practical design principle for mitigating the activity–durability trade-off of Pt electrocatalysts, and the Pt30-CYL architecture is a promising platform for high-stability HER and PEMFC applications.