Diverse C-C Bond Formation Reactions Catalyzed by Oxidized Palladium Nanoparticles Supported on Marine Shell Waste Powder via Additive-Free Deposition-Precipitation

The formation of carbon-carbon (C-C) bonds is central to modern organic synthesis. Although the use of conventional Pd-ligand complexes as homogeneous catalysts results in highly effective yields, these systems often face some limitations including high cost, difficult recyclability, and thermal stability. Here, we demonstrate the utilization of palladium (Pd)-derived metals supported on finely ground marine shell waste as a reactivity and recyclability catalyst for diverse C-C bond-forming reactions. Oyster shell powder (OSP) derived from problematic biowaste, primarily composed of calcium carbonate, provides abundant anchoring sites to immobilize Pd ions via an additive-free deposition-precipitation (D-P) method, followed by thermally-induced conversion into oxidized Pd nanoparticles (PdO NPs). Comprehensive structural and compositional analyses confirm the formation of sub-10 nm PdO NPs across the OSP surfaces and their enhanced stability. The catalytic performance (reactivity, selectivity, and recyclability) of the resulting OSP-PdO NPs is comparable to other reported systems in Ullmann coupling, homocoupling, Suzuki-Miyaura coupling, and Sonogashira coupling. Importantly, these reactions proceed under green conditions, achieving high yields without an inert atmosphere (even showing detectable activity under base-free conditions) and allowing easy catalyst recovery, highlighting the practical advantages of the quasihomogeneous catalytic system. Overall, the incorporation of nanoscale Pd-based catalysts onto marine biowaste supports offers a sustainable and cost-effective alternative to conventional homogeneous and heterogeneous catalysts for reactive and recyclable organic transformation reactions.