Design, Synthesis and Characterization of Nickel‐Functionalized Covalent Organic Framework NiCl@RIO‐12 for Heterogeneous Suzuki–Miyaura Catalysis

A series of nickel‐decorated covalent organic frameworks, NiCl@RIO‐12, were prepared using the post‐synthetic modification strategy, that is, by reacting NiCl 2 with pristine RIO‐12 under alkaline conditions. Interestingly, they retained their crystallinity and the amount of nickel incorporated could be tuned from 3.6 to 25 wt % according to the reaction conditions. The incorporation of a higher amount of nickel in NiCl@RIO‐12 consistently led to a lower Brunauer–Emmett–Teller surface area. Additionally, no agglomeration of nickel particles was found and a relatively homogeneous dispersion of nickel could be ascertained by SEM and TEM‐EDS. The paramagnetic material exhibited promising catalytic activity in Suzuki–Miyaura cross‐coupling under microwave heating. Thus, NiCl@RIO‐12 notably demonstrated good thermal stability and its recyclability showed no substantial loss of activity after 3 cycles.