Many catalytic processes rely on metal ensembles to enhance efficiency, particularly for reactions that require close metal-metal proximity. However, despite significant advancements, synthesizing hybrid metal-based catalysts remains complex, often relying on trial and error. Common methods using metal-organic frameworks or porphyrins, followed by high-temperature carbonization, face challenges like low conductivity, instability in aqueous media, and poor scalability. Extended annealing times can also cause sintering and reduce activity. Therefore, more efficient strategies are needed to integrate single atoms, clusters, and nanoparticles into hierarchical structures, maximizing metal atom density while minimizing aggregation to enable scalable production of high-performance catalysts. In this presentation, I will introduce a one-step synthesis strategy that uses bottlebrush block copolymer templates and dopamine to address these challenges in electrocatalyst design. First, I will describe how this method enables exceptional control over pore architecture within the 10-100 nm range. This is achieved through the cooperative assembly of bottlebrush block copolymers and carbon precursors, followed by carbonization using millisecond-scale photothermal pyrolysis processing. Next, I will highlight the formation of catalysts composed of isolated metal atoms, small clusters, and nanoparticles that are uniformly dispersed within a structured graphitic matrix. This approach facilitates high metal loading with excellent atomic dispersion, yielding elevated atomic and weight percentages of both Fe and Ni. Finally, I will present the performance of the resulting Fe-Ni alloy electrocatalyst, which demonstrates outstanding durability and activity under alkaline conditions. It delivers low overpotentials and high efficiency in alkaline membrane electrode assembly water-splitting systems, comparable to state-of-the-art noble metal catalysts such as Pt/C and RuO2. In-situ Raman spectroscopy and density functional theory analyses provide insight into the structural and electronic factors influencing catalytic performance. These studies reveal how atomic-scale arrangement and metal-metal interactions govern activity, emphasizing the role of cooperative active sites in hybrid catalysts. This work underscores the potential of rational design strategies for developing high-performance, earth-abundant electrocatalysts that go beyond the limitations of single-atom approaches.
