Phosphine-Based Vinyl-Covalent Organic Frameworks for Integrated Palladium Recovery and Heterogeneous Catalysis

Abstract Integrated adsorption and catalysis using recovered palladium (Pd) from waste presents an attractive paradigm for maximizing its resource utilization efficiency, while the rational design of multifunctional materials that can simultaneously regulate adsorption performance and catalytic activity remains a challenge. In this work, a series of triphenylphosphine (PPh3)-based vinyl-covalent organic frameworks (COFs) with varying PPh3 doping levels TMDF-(PPh3)x (x = 0, 0.1, 0.2, 0.3) were constructed employing a defect engineering strategy. The PPh3 moieties within the framework serve as unique Pd adsorption sites, leading to high-efficiency performance in selective Pd adsorption with high adsorption capacity (828.1 mg g–1) and fast adsorption kinetics (60 min). Meanwhile, owing to the electronic properties and spatial effect of PPh3, the recovered Pd2+@TMDF-(PPh3)0.2 can be utilized as an excellent candidate in Pd-catalyzed Suzuki-Miyaura coupling reactions. Moreover, the rigid vinyl-based framework ensures five consecutive adsorption and catalysis cycles without apparent loss of performance. This work provides a paradigm for the integrated adsorption and catalysis using recovered Pd from waste through the rational design of multifunctional COFs materials.