Engineered mesoporous ionic‐modified γ‐Fe₂O₃@hydroxyapatite decorated with palladium nanoparticles and its catalytic properties in water

Abstract

A new mesoporous organic-inorganic nanocomposite was formulated and then used as stabilizer and support for the preparation of palladium nanoparticles (Pd NPs). The properties and structure of Pd NPs immobilized on prepared 1,4-diazabicyclo[2.2.2]octane (DABCO) chemically tagged on mesoporous γ-Fe 2 O 3 @hydroxyapatite (ionic modified (IM)-MHA) were investigated using various techniques. The synergistic effects of the combined properties of MHA, DABCO and Pd NPs, and catalytic activity of γ-Fe 2 O 3 @hydroxyapatite-DABCO-Pd (IM-MHA-Pd) were investigated for the Heck cross-coupling reaction in aqueous media. The appropriate surface area and pore size of mesoporous IM-MHA nanocomposite can provide a favourable hard template for immobilization of Pd NPs. The loading level of Pd in the nanocatalyst was 0.51 mmol g −1 . DABCO bonded to the MHA surface acts as a Pd NP stabilizer and can also lead to colloidal stability of the nanocomposite in aqueous solution. The results reveal that IM-MHA-Pd is highly efficient for coupling reactions of a wide range of aryl halides with olefins under green conditions. The superparamagnetic nature of the nanocomposite means that the catalyst to be easily separated from solution through magnetic decantation, and the catalytic activity of the recycled IM-MHA-Pd showed almost no appreciable loss even after six consecutive runs.KEYWORDS aqueous media, Heck coupling reaction, mesoporous ionic-modified γ-Fe 2 O 3 @hydroxyapatite, palladium nanoparticle, sustainable organometallic platform

Highly efficient N‐doped carbon supported FeSx‐Fe2O3 catalyst for hydrogenation of nitroarenes via pyrolysis of sulfurized N,Fe‐containing MOFs

“…The magnetic property of FeS x -Fe 2 O 3 @CN-8 was measured by the Quantum Design SQUID MPMS-XL7 magnetometer. As shown in Figure 6a, the magnetic hysteresis loop for developed FeS x -Fe 2 O 3 @CN-8 catalyst exhibits a saturated magnetization of 10.4 emu g À1 at 5,500 Oe at 293 K. [63,64] As shown in Figure 6a inset, the FeS x -Fe 2 O 3 @CN-8 catalyst could also be easily separated by an external magnet and reused after thoroughly washed with ethanol, further supporting above the magnetic analysis. [65] The recyclability test (Figure 6b) suggested that FeS x -Fe 2 O 3 @CN-8 catalyst could be consecutive reused for five times without obvious loss of activity.…”

Synthesis, characterization, and application of CoFe2O4@amino‐2‐naphthol‐4‐sulfonic acid as a novel and reusable catalyst for the synthesis of spirochromene derivatives

“…[11] Some MNPs that used in catalytic applications include iron oxide (Fe 3 O 4 ), cobalt ferrite (Fe 2 CoO 4 ), maghemite ( γ -Fe 2 O 3 ), and zinc ferrite (ZnFe 2 O 4 ). [12][13][14][15] Today, great attention has been paid to cobalt ferrite (CoFe 2 O 4 ) nanocrystals with spinel structure due to their superior characteristics, such as high saturation magnetization, large surface area-tovolume ratio, and shape-dependent magnetic behavior. [16][17][18][19][20][21][22] As a review of previous studies, many functionalized CoFe 2 O 4 MNPs have been reported as a heterogeneous catalyst in multicomponent reactions (MCRs) such as CoFe 2 O 4 @SiO 2 @CPTMS, [13] CoFe 2 O 4 @SiO 2 -SO 3 H, [23] CoFe 2 O 4 @SiO 2 -PTA, [24] CoFe 2 O 4 /TMU-17-NH 2 , [25] CoFe 2 O 4 @l-asparagine-Cu/ Ni, [26] CoFe 2 O 4 @glycine-M, [27] CoFe 2 O 4 @Pr.…”

Oxime‐derived palladacycle Immobilized in an Ionic Liquid Brush as an Efficient and Reusable Catalyst for Mozoroki‐Heck Reaction in Neat Water

“…Most of the so‐called water phase reactions were performed with the aid of organic solvents, such as DMF–H 2 O, CH 3 CN–H 2 O, or EtOH–H 2 O . Although there are a few reports of the Mizoroki–Heck reaction in neat water, these catalytic systems usually suffer from at least one of the following shortcomings: the need for complicated and/or toxic ligands; the use of surfactants or phase transfer catalyst to improve solvation of the organic substrate; the need for complicated and/or toxic ligands; and the lack of reusability. In past decades, many efforts have been made to solve these problems through the development of active, reusable catalysts and more facile and benign procedures, but satisfactory solutions are still a challenge.…”