Synthesis and evaluation of HfO as a prospective filler in inorganic-organic hybrid membranes based on Nafion for PEM fuel cells.

Hybrid inorganic-organic Nafion membranes modified with metal oxides (typically TiO, ZrO, WO) are a good alternative for fuel cell applications. However, one of their main limitations is associated with their relative low proton conductivity at temperatures above 80 °C. In this work, we overcome this issue using HfO as a filler.