Ultra-low Pt loading catalyst on (Nb–Ti)2AlC support as advanced material for low-temperature fuel cell application

Abstract

The oxygen reduction reaction was investigated at 10 monolayers (MLs) of Pt electrodeposited on (Nb–Ti)2AlC substrate. Following the discussion of detailed kinetics and electrodeposition optimisation in the authors’ previous paper, the focus of this research was on stability testing. Previously performed optimisation results showed the best activity shown by 10 monolayers of Pt. Catalyst characterisation was performed by scanning electron microscopy, X-ray photoelectron spectroscopy and transmission electron microscopy. SEM, EDS and XPS analysis showed that the surface was covered with a homogeneous layer of Pt. TEM analysis of a cross-section confirmed the presence of Pt layer of thickness ∼3.5 nm, corresponding to the 10 MLs of Pt. Although the mass activity for the ORR at 0.8 V vs. RHE of 37.4 A g−1 was comparable with the best one for the Pt/C benchmark, US Department of Energy Protocols revealed excellent catalyst stability – the loss of electrochemically active surface area (EASA) was found to be only 9.3%.