Structural transformation of an imidazolium-templated two-dimensional aluminophosphate and its proton conduction under anhydrous conditions

We focused on an imidazolium-templated two-dimensional aluminophosphate (C3N2H5)[Al(HPO4)2(H2O)2] (denoted as AlPO-PC-1) with complex hydrogen bonding network to show inherent proton conductivity under anhydrous conditions. Inherent proton conductivity was studied under a N2 atmosphere (zero-humidity conditions). Notably, the AlPO-PC-1 suffers the ordered-to-disordered structural transformation induced by the increase of temperature, which influences the proton conduction process and conduction mechanism. The resulting material shows a proton conductivity of 1.1×10−4 S cm−1 at 150 °C. At 25-100 °C, the proton conduction is controlled by Grotthuss mechanism. While at 115-150 °C, the transformation of the structure affords highly mobile proton carriers and both vehicle and Grotthuss mechanism contribute to the proton conduction.