Liquid Palladium for High-Turnover Carbon-Carbon Bond Formation

Carbon-carbon (C─C) bond formation is a key step in diverse chemical processes and requires high-performance catalysts to enable energy-efficient technologies. Here, we present liquid Pd catalysts, formed by dissolving Pd in liquid Ga, for high-turnover C─C coupling reactions. The liquid Pd catalyst achieved a turnover frequency of 2.5 × 10⁸ hour⁻¹ for a model coupling reaction at 70°C, surpassing all reported Pd catalysts by 1000-fold. Our results show that Pd atoms in the Ga matrix are liquid-like, exhibiting unique electronic and interfacial properties that substantially lower the energy barrier and enhance reaction kinetics. The system retained full activity over five cycles and showed no Pd leaching, highlighting the transformative potential of liquid-phase metals to advance high-throughput and sustainable C─C bond-forming strategies.