Pd Nanoparticles on Melamine Sponges for Recyclable\nand Scalable Solar-Thermal Catalysis in Suzuki Coupling Reactions

Solar-thermal materials directly\nconvert sunlight into heat, enabling\nthe heating of reaction solutions without relying on electricity or\nfossil fuels. Although eco-friendly solar-thermal Suzuki coupling\ncatalysis has recently been reported, its scalability must be enhanced\nfor practical synthesis applications. In this study, an eco-friendly\nand scalable Suzuki coupling catalysis system was demonstrated using\nPd nanoparticle monolayer-coated sponges, which exhibit exceptional\nsolar-thermal and catalytic activities under multiphasic reaction\nconditions. The product mass per illuminated area was improved significantly\ncompared with the earlier solar-thermal catalysis system. Gram-scale\nSuzuki coupling catalysis with Pd nanoparticle monolayer-coated sponges\nunder simulated 1 sun illumination over an area of 3.14 cm<sup>2</sup> was demonstrated successfully without the use of additional energy\nfor solvent heating. The multicycle use of solar-thermal heating and\nheterogeneous catalytic activities of Pd nanoparticle monolayer-coated\nsponges was also demonstrated.