Proton-conducting tin phosphates for electrochemical applications operating at intermediate temperatures

3^rd International Conference and Exhibition on Materials Science & Engineering

October 06-08, 2014 Hilton San Antonio Airport, USA

Masahiro Nagao

Scientific Tracks Abstracts: J Material Sci Eng

Abstract :

This report describes proton conduction in doped SnP2O7 at temperaturesof 100-300°C. When Sn4+ is partially replaced by In3+, the proton conductivity of 10 mol% In3+- doped SnP2O7 is greater than 10-1 S cm-1at temperaturesof 125-300°C. Conductivity reaches 1.95 × 10-1 S cm-1 at 250°C. Highly conductive protons in In3+- doped SnP2O7 are achieved through a reaction between water vapor and an electron hole, which is introduced by the low-valence atom substitution for Sn4+. Because such high conductivity in an intermediate temperature region has never been reported, we have launched the concept for application to electrochemical devices such as fuel cells, gas sensors, reactors and batteries. For example, a salient benefit of the intermediate-temperature operationis that fuel cells using a Pt catalyst can be freed from CO poisoning. The fuel cell showed high tolerance toward 10% CO in fuel and showed the high power density of 264 mW cm-2 at 250 °C. When we used the dimethyl ether as a fuel, the fuel cell with PtRu/C anode achieved the peak power density of 78 mW cm-2 at 300°C. Moreover, because high catalytic activity is expected when the operating temperature is increased, non-Pt catalysts were explored as alternative anodes. Among the tested candidates, Mo2C-ZrO2/C anode showed a cell performance comparable to that of the Pt/C anode.

Biography :

Masahiro Nagao completed his PhD at Nagoya University. He has authored or co- authored more than 25 publications in peer-reviewed journals. His research interests include high ionic conductive materials and their application to electrochemical devices.