Liquid Metal-Enabled Rapid Structure Ordering of Intermetallic Nanocrystals with Electronic Modulation

Abstract

p-block metal (e.g., Ga)-based intermetallic nanocrystals with atomically ordered d-p hybrid structures are promising for electrocatalytic nitrate reduction reaction (NO3RR). However, traditional synthesis requires prolonged annealing, causing high energy consumption, Ostwald ripening/elemental segregation, and undermining active-site uniformity/ordered architectures. Here, a rapid thermal diffusion-assisted heating method (1 min) enabled by low-enthalpy liquid Ga as a dynamic reaction reservoir is presented, which boosts exothermic alloying thermodynamics and facilitates atomic-level Ru/Ga/In intermixing for rapid synthesis of composition-controlled, small-sized (8.7 +/- 2.0 nm) In-doped RuGa intermetallic catalysts (In-RuGa IMCs). XAFs analysis confirms atomic-level dispersion of Ga and Ru in a well-ordered lattice. The catalyst achieves 97.3% Faradaic efficiency and a yield of 6.43 mg h-1 cm-2 at -0.6 V (vs RHE), benefiting from the electron-rich environment around Ru contributed by neighboring Ga and In. In situ/ex situ characterizations and computational modeling reveal the link between the NO3RR activity and d-p hybrid structures. Compared to traditional methods, The roll-to-roll synthesis setup demonstrates significant advantages in environmental and technoeconomic aspects, reducing greenhouse gas emissions, energy consumption, and production costs by several times, while also enhancing scalability and sustainability. This highlights the potential of this strategy for large-scale, low-cost, and eco-friendly manufacturing.