Dynamic Vibration-Coupled Energy Transfer for Boosting ORR Catalysts in Fuel Cells
Chenjia Liang, Jun Yao, Xiaoxia Hou, Liang Li, Ningze Gao, Haoyu Lu, Ruiyao Zhao, Xiangke Guo, Nianhua Xue, Luming Peng, Xuefeng Guo, Yan Zhu, Weiping Ding
Abstract
We demonstrate here a promising yet challenging method to produce highly active catalysts by utilizing exothermic adsorption to spur endothermic desorption steps through dynamic surface energy transfer. Taking the oxygen reduction reaction (ORR) catalyst as an example, we implement dynamically vibration-coupled energy transfer (VCET) by anchoring flexible tert -butylsulfonylcalix[4]arene (tBuC[4]A) on PtCo NPs, holding the exothermic energy of oxygen adsorption at the surface for a prolonged time to compensate the endothermic process, e.g., OH* → H 2 O, on adjacent Pt sites. The above process is summarized as “adsorption–spurring–desorption”. Based on the machine learning model, theoretical simulations reveal how the vibrational excitation of tBuC[4]A (0.126 eV per molecule), triggered by O 2 adsorption on PtCo and transferred by phonon–phonon scattering, resonantly weakens OH* binding, slashing desorption barriers by 51% (0.375 → 0.183 eV) and achieving 13.2% energy utilization. This dynamic energy management significantly promotes the performance of the catalyst and the fuel cell: 1.03 A mg Pt –1 mass activity and 2.07 W cm –2 peak output power under 0.1 mg Pt cm –2 loading, surpassing DOE targets. Characterization results of in situ FTIR and Raman spectroscopy and kinetic measurements fully support the mechanism and suggest the coupling of the activation of the O–O bond and optimized OH* desorption. The VCET mechanism establishes a blueprint for dynamic promotion beyond conventional strategies to develop high-performance heterogeneous catalysts.