An experimental approach to reduce precious metal loading on porous transport layer by using magnetron sputtering method for PEMWE application
Anurag Anurag, Abhay Gupta, Samaneh Shahgaldi
Abstract
• Multi-layered NbPt coating was sputtered on the Ti-based porous transport layer. • Electrochemical behavior of co-deposited and multi-layered NbPt coatings were compared. • Multi-layered NbPt coating enhanced Galvanic protection and electrochemical stability. • Multi-layered NbPt coating exhibited higher durability over commercial sample. The extravagant cost of Pt-coated porous transport layers (PTLs) had augmented the already high price of stack components in Proton exchange membrane water electrolyzers (PEMWE). To curtail this high cost, there is a pressing need to replace the expensive Pt coatings with cost-effective materials on Ti PTLs. Hence an attempt is being made to reduce the Pt loading by sputtering co-deposited and multi-layered NbPt coatings on Ti PTLs. The findings showed that the multi-layered NbPt coating exhibited superior corrosion resistance, enhanced durability, and higher conductivity than its co-deposited counterpart under ex-situ environment of PEMWE. The multi-layered NbPt coating was subsequently compared with commercial Pt-coated PTL under both ex-situ and in-situ operating conditions. It was revealed that the multi-layered NbPt coated PTL showcased longer durability and similar ICR compared to the commercial PTL under ex-situ conditions. During the in-situ testing, multi-layered NbPt coating with thin layer of Pt (50 nm), performed (2.050 V @2.0 A/cm 2 ) equivalently to the commercial Pt (200 nm) coating (2.044 V @2.0 A/cm 2 ), making it a viable PTL coating alternative.