Polypyrrole@Pd solar-thermal catalyst for eco-friendly and scalable multiphasic Suzuki coupling reactions

Solar-thermal materials enable the heating of reaction solutions in organic reactions without consuming fossil fuels or electricity. In this study, nanostructured polypyrole@Pd was utilized with solar-thermal, catalytic, and Pickering emulsifier functionalities to successfully demonstrate eco-friendly and scalable Suzuki coupling reactions. Pd-catalyzed multiphasic Suzuki coupling reactions were accelerated with high conversions through solar-thermal heating and the formation of Pickering emulsions in a phase-separated, highly concentrated reaction mixture using polypyrole@Pd. Increasing the interfacial area by forming a Pickering emulsion facilitates mass transfer between the two miscible liquid phases, which is crucial for multiphasic reactions. Gram-scale synthesis under solar illumination over an area of 3.14 cm was successfully achieved, and the multiple usability of polypyrrole@Pd was demonstrated over 20 cycles.