Highly Efficient Nanosized Mesoporous CuMgAl Ternary Oxide Catalyst for Nitro-Alcohol Synthesis: Ultrasound-Assisted Sustainable Green Perspective for the Henry Reaction

Mohamed Mokhtar; Budoor F A Alhashedi; Heba A Kashmery; Nesreen S Ahmed; Tamer S Saleh; Katabathini Narasimharao

doi:10.1021/acsomega.9b04212

Highly Efficient Nanosized Mesoporous CuMgAl Ternary Oxide Catalyst for Nitro-Alcohol Synthesis: Ultrasound-Assisted Sustainable Green Perspective for the Henry Reaction

ACS Omega. 2020 Mar 18;5(12):6532-6544. doi: 10.1021/acsomega.9b04212. eCollection 2020 Mar 31.

Authors

Mohamed Mokhtar¹, Budoor F A Alhashedi¹, Heba A Kashmery¹, Nesreen S Ahmed², Tamer S Saleh^{3

4}, Katabathini Narasimharao¹

Affiliations

¹ Chemistry Department, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah 21589, Saudi Arabia.
² Department of Therapeutic Chemistry, Pharmaceutical and Drug Industries Research Division, National Research Center, El Buhouth St., Dokki, Cairo 12622, Egypt.
³ Chemistry Department, Faculty of Science, University of Jeddah, P.O. Box 80329, Jeddah 21589, Saudi Arabia.
⁴ Green Chemistry Department, National Research Centre, El Buhouth St., Dokki, Cairo 12622, Egypt.

Abstract

Nanosized mesoporous CuMgAl ternary oxide catalysts were prepared by thermal decomposition of CuMgAl-layered double hydroxides at 500 °C with nominal Cu/Mg/Al ratios of 1:1:1 (Cu-LDH-I), 1.5:0.5:1 (Cu-LDH-II), and 2:0:1 (Cu-LDH-III). The synthesized catalysts were characterized by inductively coupled plasma atomic emission spectroscopy (ICP-AES), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), Fourier transform infrared (FTIR) spectroscopy, CO₂-TPD, and N₂ physisorption analysis techniques. The catalytic activity of the synthesized materials was investigated for the Henry reaction between nitromethane and numerous aldehyde derivatives under ultrasonic irradiation. The three CuMgAl ternary oxide catalysts exhibited a high catalytic activity, forming nitro alcohol products with 100% atom economy. The CuMgAl-I catalyst derived from Cu-LDH-I offered high turnover frequencies (TOFs in the synthesis of all of the nitro alcohols in shorter reaction times). The superior catalytic activity of the CuMgAl-I sample is attributed to the synergistic effect between the physicochemical properties of the catalysts and ultrasonic irradiation. The HRTEM analysis of the used CuMgAl-I catalyst revealed the evidence for the cavitation collapse, which causes localized deformation and surface erosion. Moreover, the synthesized catalysts also exhibited robust sustainable activity that resisted deactivation over repeated usage. The present example of ultrasonic-assisted catalyzed organic synthesis represents a novel strategy for the solvent-free green synthesis of nitro-alcohols by the Henry reaction with 100% atom economy.