Zirconia/Porous Carbon Derived from UiO‐66 as an Efficient Electrocatalyst Carrier for Oxygen Reduction Reactions

The development of high‐performance, low‐platinum (Pt)‐loading catalysts for the oxygen reduction reaction (ORR) remains a critical challenge in proton exchange membrane fuel cells. Zirconium dioxide‐carbon composite materials are prepared using the Zr‐based metal‐organic framework UiO‐66 as a precursor. The support structure is modulated by controlling the pyrolysis conditions (700 °C, 800 °C, and 900 °C). Platinum nanoparticles are deposited onto the ZrO 2 ‐carbon composite framework using ethylene glycol as the reducing agent, yielding low‐Pt‐content Pt/U‐X catalysts (X = 700, 800, 900). The findings demonstrate that the Pt/U‐X catalysts exhibit superior electrocatalytic activity compared with commercial Pt/C catalysts. Pt/U‐800 displays the highest mass activity (796.9 mA mg Pt −1 ), which is 3.64 times higher than commercial Pt/C (219.2 mA mg Pt −1 ). Furthermore, Pt/U‐800 achieves 1250 mA cm −2 at 0.6 V and reaches a peak power density of 1820 mW cm −2 in fuel cell tests. The one‐step composite of ZrO 2 and carbon, formed through the pyrolysis of UiO‐66, facilitates an interfacial structure between ZrO 2 and Pt, optimizing the hierarchical pore structure of the support, and providing a promising, cost‐effective alternative to traditional Pt/C catalysts for fuel cell cathod.