Pt catalyst protected by graphene nanopockets enables lifetimes of over 200,000 h for heavy-duty fuel cell applications.

Proton exchange membrane fuel cells feature considerable scalability advantages over lithium-ion batteries for heavy-duty-vehicle applications. The different driving behaviours and operating conditions of heavy-duty vehicles pose challenging requirements, particularly on fuel cell lifetime and efficiency. Here we report the design of a graphene-nanopocket-protected, pore-confined and electrochemically accessible Pt nanocatalyst supported on Ketjenblack carbon for heavy-duty-vehicle applications. The membrane electrode assembly made from these nanocatalysts delivers an initial mass activity of 0.74 A mg and a high rated power density of 1.08 W cm, as well as extraordinary long-term durability with an ultrasmall rated power loss of 1.1% after 90,000 aggressive square-wave cycles. The remarkable activity and durability throughout the operation conditions promise an unprecedentedly long fuel cell lifetime of over 200,000 h and high peak efficiency of 71.9%, making it highly attractive for emerging heavy-duty fuel cell applications.