Encapsulation of Nickel Nanoparticles and Homopoly(Vinylsulfonic Acid) in Mesoporous Carbon CMK-3 as an Acid–Metal Bifunctional Catalyst for Tandem Reductive Amination

Facile and clean transformation for synthesizing secondary arylamines through one-pot reductive amination of aniline has
been catalyzed by supported nickel nanocluster and poly(vinylsulfonic acid) into mesoporous carbon CMK-3 (Ni/PVSA/
CMK-3) as a bi-functional metal/acid heterogeneous catalyst. Vinylsulfonic acid has been polymerized in CMK-3 pores by
an in situ method. The process was run in the presence of NaBH4 at room temperature, in a short reaction time, and without
secondary product. Various characterization techniques, including FT-IR, XRD, TG, BET, SEM, TEM, DRS-UV, and
AAS were employed to disclose the physical and chemical properties of the catalyst. Reaction results demonstrate that the
optimized Ni/PVSA/CMK-3 catalyst shows comparable catalytic performance thanks to the nickel metals and the acidic
nature of polymer incorporated in mesoporous channels of CMK-3. Besides being eco-friendly (using water as solvent), the
method has several advantages such as simple work-up procedure and moderate to high-yield. This catalyst was easily
filtered and reused without noticeable loss of activity after 10 runs.