Facile Synthesis and Characterization of Palladium@Carbon Catalyst for the Suzuki-Miyaura and Mizoroki-Heck Coupling Reactions

• Published in: Applied sciences Vol. 11; no. 11; p. 4822
• Main Authors: Alshammari, Hamed M., Aldosari, Obaid F., Alotaibi, Mohammad Hayal, Alotaibi, Raja L., Alhumaimess, Mosaed S., Morad, Moataz H., Adil, Syed Farooq, Shaik, Mohammed Rafi, Islam, Mohammad Shahidul, Khan, Mujeeb, Alwarthan, Abdulrahman
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.06.2021
• Subjects: Acids; Acrylic acid; Activated carbon; Aqueous solutions; Aromatic compounds; carbon; catalyst; Catalysts; Catalytic activity; Chemical reactions; Cross coupling; Halides; Mizoroki–Heck; Nanoparticles; Optimization; Palladium; Pore size; Reducing agents; Scanning electron microscopy; Suzuki–Miyaura coupling; X-ray diffraction; X-ray spectroscopy
• ISSN: 2076-3417; 2076-3417
• DOI: 10.3390/app11114822

Palladium-based carbon catalysts (Pd/C) can be potentially applied as an efficient catalyst for Suzuki–Miyaura and Mizoroki–Heck coupling reactions. Herein, a variety of catalysts of palladium on activated carbon were prepared by varying the content of ‘Pd’ via an in situ reduction method, using hydrogen as a reducing agent. The as-prepared catalysts (0.5 wt % Pd/C, 1 wt % Pd/C, 2 wt % Pd/C and 3 wt % Pd/C) were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and Brunauer–Emmett–Teller (BET) analyses. The catalysts were tested as a coupling catalyst for Suzuki–Miyaura coupling reactions involving aryl halides and phenyl boronic acid. The optimization of the catalyst by varying the palladium content on the activated carbon yielded Pd/C catalysts with very high catalytic activity for Suzuki reactions of aryl halides and a Mizoroki–Heck cross-coupling reaction of 4-bromoanisol and acrylic acid in an aqueous medium. A high ‘Pd’ content and uniform ‘Pd’ impregnation significantly affected the activity of the catalysts. The catalytic activity of 3% Pd/C was found to make it a more efficient catalyst when compared with the other synthesized Pd/C catalysts. Furthermore, the catalyst reusability was also tested for Suzuki reactions by repeatedly performing the same reaction using the recovered catalyst. The 3% Pd/C catalyst displayed better reusability even after several reactions.