Reducing Irreversible Performance Losses via a Graphene Oxide Buffer Layer for Proton-Exchange Membrane Fuel Cells

Abstract

Alloy catalysts are promising for proton-exchange membrane fuel cells but are difficult to realize high-durability operation because the dissolution of Pt–M (M = Co, Ni, etc.) metals inevitably accelerates irreversible performance degradation. Here, we propose a buffer layer solution that inserts a trace layer of a graphene oxide (GO) film between the PEM and the alloy catalyst layer to mitigate the poison effect. To distinguish the irreversible and reversible losses, two typical recovery procedures (shutdown and JRC-based protocols) being part of a fuel cell dynamic load cycle durability test are characterized. The electrochemical evaluation reveals that GO-1 μg/cm2 enables a higher initial performance and stability. Furthermore, the GO buffer layer design allows the realization of membrane electrode assemblies with a highly homogeneous current density distribution and a low accessible mass transport resistance. Thanks to the ion sieving effect in the GO buffer layer, high anti-poisoning and stability during the accelerated stress test process are ensured.

Coaly Graphite as an Eco-Friendly Material in the Microporous Layer of Proton Exchange Membrane Fuel Cells

“…Additionally, the CB + 50% CG + GO MPL is expected to be stable in the long term. First, its raw materials, CB, CG, and GO, are stable under air and humidified conditions, which have been proven by the literature. ,,, Second, GO can mitigate crack formation (Figure c compared with a), which further improves mechanical strength and long-term stability. − Third, a recent report has shown that 1 μg cm –2 GO acts as the buffer layer for PEM fuel cells and improves the stability of the catalyst, while it is also the case here, and is expected to improve the stability of the catalyst at the MPL-CL interface. So, it is expected that this structure can be stable during PEM fuel cell operation.…”

“…31,32,40,41 Second, GO can mitigate crack formation (Figure 3c compared with 3a), which further improves mechanical strength and long-term stability. 42−44 Third, a recent report has shown that 1 μg cm −2 GO acts as the buffer layer for PEM fuel cells and improves the stability of the catalyst, 45 while it is also the case here, and is expected to improve the stability of the catalyst at the MPL-CL interface. So, it is expected that this structure can be stable during PEM fuel cell operation.…”