A novel ligand-free heterogeneous catalyst was synthesized via pyrolysis of Samanea saman pods to produce carbon nanospheres (SS-CNSs), which served as a carbon support for immobilizing palladium nanoparticles through an in situ reduction technique (Pd/SS-CNS). The SS-CNSs effectively integrated 3% of Pd on their surfaces with no additional activation procedures needed. The nanomaterials obtained underwent thorough characterization employing various techniques such as FT-IR, XRD, FE-SEM, TEM, EDS, ICP-AES, and BET. Subsequently, the efficiency of this Pd/SS-CNS catalyst was assessed for the synthesis of biaryl derivatives via Suzuki coupling, wherein different boronic acids were coupled with various aryl halides using an environmentally benign solvent mixture of EtOH/H₂O and employing only 0.1 mol% of Pd/SS-CNS. The catalytic system was conveniently recovered through centrifugation and demonstrated reusability without any noticeable decline in catalytic activity. This approach offers economic viability, ecological compatibility, scalability, and has the potential to serve as an alternative to homogeneous catalysis.

中文翻译：

---

可持续碳质纳米材料负载钯作为铃木-宫浦偶联的有效无配体多相催化剂

通过热解Samanea saman pod 生成碳纳米球（SS-CNS），合成了一种新型无配体多相催化剂，该催化剂可作为通过原位还原技术（Pd/SS-CNS）固定钯纳米颗粒的碳载体。 SS-CNS 有效地将 3% 的 Pd 集成在其表面，无需额外的激活程序。采用 FT-IR、XRD、FE-SEM、TEM、EDS、ICP-AES 和 BET 等各种技术对获得的纳米材料进行了彻底的表征。随后，通过Suzuki 偶联评估了这种 Pd/SS-CNS 催化剂合成联芳基衍生物的效率，其中使用环境友好的 EtOH/H ₂ O 溶剂混合物并仅使用 0.1 Pd/SS-CNS 的 mol%。该催化体系可以通过离心方便地回收，并表现出可重复使用性，催化活性没有任何明显下降。这种方法具有经济可行性、生态相容性、可扩展性，并且有潜力作为均相催化的替代品。