Sodium Tungstate Supported on a Three‐dimensional and Networked SBA‐15 for Knoevenagel Reaction

Abstract

Sodium tungstate (ST) supported on a three-dimensional and networked SBA-15 (3D-SBA-15) was utilized as a novel efficient catalyst for the Knoevenagel condensation of aldehydes with active methylene compounds such as malononitrile and ethyl cyanoacetate to afford substituted olefins through the conventional magnetic stirring or under ultrasound irradiation. ST/3D-SBA-15 catalyst was prepared using an incipient wetness impregnation method and confirmed by series of characterizations such as Fourier-transform infrared spectra (FT-IR), scanning electron microscope (SEM), X-ray diffraction (XRD), N 2 adsorption-desorption and inductively coupled plasma-optical emission spectroscopy. The reaction proceeded smoothly under the both stirring and ultrasound-assisted conditions at room temperature. The 30ST/3D-SBA-15 catalyst with 30 wt% loading of Na 2 WO 4 showed the highest catalytic performance with excellent yield within short time, and improvements were observed by carrying out the reactions under ultrasound irradiation. In addition, the solvent effect was significant in this work, and the optimum solvent was ethanol and water with volume ratio of 1 : 1.

Design, Synthesis and Characterization of Aurone Based α,β‐unsaturated Carbonyl‐Amino Ligands and their Application in Microwave Assisted Suzuki, Heck and Buchwald Reactions

“…ethyl (E)‐2‐cyano‐3‐(p–tolyl)acrylate (7 k) : [58] White Solid; Yield 91%; m. p 90–91 °C; 1 H NMR (400 MHz, CDCl 3 ) δ 8.20 (s, 1H), 7.89 (d, J =8.2 Hz, 2H), 7.29 (d, J =8.1 Hz, 2H), 4.36 (q, J =7.1 Hz, 2H), 2.42 (s, 3H), 1.38 (t, J =7.1 Hz, 3H); 13 C NMR (100 MHz, CDCl 3 ) δ 162.86, 155.08, 144.73, 131.34, 130.12, 128.97, 115.85, 101.68, 62.67, 21.94, 14.25.…”

Organic Additive Assisted Ordered Mesoporous Ni/Al2O3 Catalyst for CO2 Methanation

“…Ordered mesoporous materials with large surface areas and controlled specific morphologies have drawn great attention in catalysis as well as in materials science. Silicon‐based ordered mesoporous materials, such as MCF, SBA‐15, or KIT‐6, have been widely reported; however, due to the weak interaction between metal and silicon‐based support, metal particles tend to migrate from the mesoporous channel to the outer surface at high temperature, resulting in severe metal‐sintering and decreased activity. On the contrary, the ordered mesoporous alumina (OMA) has a strong interaction with the metal particles, and the OMA catalyst can effectively restrain the sintering of active metal nanoparticles in a fixed space.…”

WOx‐Modified Ni Catalyst Supported on Mesoporous Silica with Extra‐Large Mesopores for CO Methanation

“…The ordered mesoporous material has been widely used as the support in catalysis, which not only offers a large surface area for the high dispersion of active metals but also exerts a spatial restriction on metal particles, hampering their sintering as well as coke formation. Over the years, many ordered mesoporous silica materials with various morphological and topological characteristics have been reported as efficient supports, including mobil composition of matter (MCM)‐41, MCM‐48, Santa Barbara mesoporous silica (SBA‐15) . The pore structures of some of them are 1D with small pore sizes, which limit the diffusion or mass transfer in the channels and suffer the blockage of pores during catalysis or separation processes.…”