Two-dimensional dual-mesoporous catalytic networks with coexisting Pt single atoms and clusters for boosted oxygen reduction reaction

Single atom-cluster coexisting catalysts offer high oxygen reduction reaction (ORR) potential but often suffer from synthesis complexity and poor scalability. Here, we report a green and scalable molten-salt templating strategy using NaCl to construct a two-dimensional ultrathin mesoporous carbon-supported Pt catalyst (Pt_SA-NC/2D-OMCNs) <i>via</i> simple calcination and water washing. The catalyst integrates dual mesopores: small mesopores (∼3.8 nm) increase active site density, while large mesopores (20-30 nm) enhance mass transport. Combined with nitrogen dopants and edge defects that anchor Pt species, this architecture ensures uniform dispersion and structural stability of Pt single atoms and clusters. Benefiting from this well-engineered dual-mesoporous catalytic network, Pt_SA-NC/2D-OMCNs exhibit excellent ORR activity and long-term durability in both three-electrode systems and practical fuel cell tests. This work presents a scalable design strategy for constructing high-performance, low-Pt ORR catalysts, and broadens the application scope of atom-cluster coexisting systems in fuel cell electrocatalysis.