Developing a Unique Hydrogen-Bond Network in a Uranyl Coordination Framework for Fuel Cell Applications br

Crystalline materials with persistent high anhydrous proton conductivity that can be directly used as a practical electrolyteof the intermediate-temperature proton exchange membrane fuel cellsfor durable power generation remain a substantial challenge. Thepresent work proposes a unique way of the axial uranyl oxo atoms ashydrogen-bond acceptors to form a dense hydrogen-bonded networkwithin a stable uranyl-based coordination polymer,UO2(H2PO3)2(C3N2H4)2(HUP-3). It exhibits stable and efficientanhydrous proton conductivity over a super-wide temperature range(-40-170 degrees C). It was also assembled into a H2/O2fuel cell as theelectrolyte and shows a high electrical power density of 11.8 mWmiddotcm-2at 170 degrees C, which is among one of the highest values reported fromcrystalline solid electrolytes. The cell was tested for over 12 h without notable power loss