Low precious metal loading porous transport layer coating and anode catalyst layer for proton exchange membrane water electrolysis

A mixed metal oxide-coated Ti felt was constructed for use as a porous transport layer (PTL) in a proton exchange membrane (PEM) water electrolyzer. The PTL was fabricated by coating Ti felt with 0.43 mgTaOx cm−2 and 1 mgIr + Ru cm−2 IrO2–RuO2-TaOx using a thermal decomposition method. The coated Ti felts exhibited high conductivity, mass transport performance, stability and oxygen evolution reaction (OER) catalytic activities. The stability of IrO2–RuO2-TaOx coating obviously improved than traditional electroplated Pt coating. Using the PTL, a single cell performance of 1.836 V @ 2000 mA cm−2 was achieved at 80 °C under ambient pressure with 1 mg cm−2 of precious metal in anode CL. However, the precious metal loading is about 2 mg cm−2 in common PEM electrolyzer anode catalyst layer (CL). The IrO2–RuO2-TaOx-coated Ti felt proved to be a promising low-cost PTL for PEM water electrolysis with high performance.