Nitrided Pt-Ni-Co Nanoparticle Catalyst for Durable PEMFC ORR

The patent employs a ternary alloy composite material comprising Pt, Ni, and Co metals in specific ratios (Pt:Ni:Co = 1:0.5:0.5 to 1:2:2). This composite structure combines the high catalytic activity of Pt with the stabilizing effects of Ni and Co, creating a material that maintains both high ORR activity and enhanced durability under acidic fuel cell conditions. The synergistic interaction between the three metals resolves the contradiction by providing both activity and stability that neither binary alloys nor pure Pt can achieve alone.

The patent creates a core-shell structure where the Pt-rich shell provides high catalytic activity for ORR, while the Ni-Co rich core provides structural stability and resistance to dissolution. This local differentiation of material properties allows the outer surface to optimize for activity while the inner structure optimizes for durability, resolving the contradiction between activity and long-term stability.

The patent optimizes the particle size parameter to 3-10 nm, which provides sufficient surface area for high catalytic activity while being small enough to minimize agglomeration tendencies. Additionally, the specific Pt:Ni:Co ratio (1:0.5:0.5 to 1:2:2) is optimized to balance activity and stability, and the annealing temperature (400-820°C) is controlled to achieve the desired crystalline structure and particle size distribution. These parameter optimizations resolve the contradiction between activity and stability.

The patent performs preliminary annealing treatment at 400-820°C for 1-20 hours to pre-stabilize the catalyst structure before use. This preliminary action creates a stable crystalline structure and prevents subsequent agglomeration and dissolution during fuel cell operation, thereby maintaining catalytic activity over extended periods.

The patent creates a ternary composite material where Pt provides catalytic activity, Ni enhances activity and modifies electronic structure, and Co provides structural stability and resistance to acidic corrosion. The specific composition ratios (Pt:Ni:Co = 1:0.5:0.5 to 1:2:2) are optimized to achieve the right balance between activity enhancement and structural stability, resolving the contradiction by distributing functional roles across three metals rather than relying on binary combinations.

The patent creates a core-shell structure where the Pt-rich shell provides high catalytic activity for ORR, while the Ni-Co rich core provides structural stability and resistance to dissolution. This local differentiation of material properties allows the outer surface to optimize for activity while the inner structure optimizes for durability, resolving the contradiction between activity and long-term stability.