Dehydrogenation Catalysts for Synthesis of O-Phenylphenol via Cu/Ni/Mg/Al Hydrotalcite-Like Compounds as Precursors

Abstract

A series of copper containing catalysts were prepared by calcination of Cu/Ni/Mg/Al hydrotalcite-like precursors, using the coprecipitation method. The materials were characterized and show a well-crystallized layered structure of hydrotalcite with smaller Cu 0 particles. We also studied their catalytic performance for conversion of 2-(1-cyclohexenyl) cyclohexanone into o-phenylphenol. The catalysts containing Ni showed higher catalytic activity; the optimum stability occurred when the Ni 2+ :(Ni 2+ + Cu 2+ ) atomic ratio was 0.4. The combination of Cu and Ni can greatly improve the stability and activities of the catalyst.

Full-Spectrum Photocatalytic Activity of ZnO/CuO/ZnFe2O4 Nanocomposite as a PhotoFenton-Like Catalyst

“…Hydrotalcite-like compounds (HLCs), or layered double hydroxides (LDHs), are a class of anionic clays with brucite-like sheets consisting of adjustable mixed metal hydroxides and interlayer anions [1,2]. Many divalent cations, such as Mg 2+ , Zn 2+ , Co 2+ , Ni 2+ , Mn 2+ , Fe 2+ and Cu 2+ , and trivalent cations, such as Al 3+ , Fe 3+ , Cr 3+ , Mn 3+ , Ga 3+ and In 3+ , have been reported to be involved in the preparation of HLCs [1][2][3][4][5]. By calcinating the HLCs at high temperatures, mixed metal oxides (MMOs) with heterojunctions at metal oxide interfaces are formed due to dehydration, dehydroxylation and anion decomposition [6].…”

Effect of Synthetic Parameters on Crystallinity of Hydrotalcite-Like Anionic Clays with Elucidation and Identification through X-Ray Diffraction Analysis

“…XRD patterns displayed a typical pattern of hydrotalcite-like materials. The characteristic (003), (006), (009), (015), (018), (110) and (113) lattice plane diffraction peaks were observed for HTs/LDHs with ≅ 2θ value 11.6°, 23.4°, 34.8°, 38.8°, 46.3°, 60.85° and 62.1°, which indicates the well-developed layer structure of HTs/LDHs. The interlayer spacing 'd' formed from the metal hydroxide sheet (~ 4.7 Å), and the gallery region that contains the intercalated anions (~ 2.8 Å or higher value) (31)(32)(33).…”

“…The anion exchange capacity, basic nature due to the presence of Bronsted-Lewis acidic and basic sites, high surface area, increased basal spacing and memory effect or selfhealing property make them an effective catalyst and adsorbent material (95,(103)(104)(105)(106)(107)(108)(109). Due to their unique chemical structure and composition, as well as tunable interlayer galleries, HTs/LDHs can be used in a large number of applications, including delivery agents in bioactive and agrochemicals, adsorbents, catalysis, recycling of plastic material, flame retardants and packaging materials (110)(111)(112)(113)(114)(115)(116). These materials also effectively used in energy storage systems e.g., electrode material in batteries, supercapacitors and dyesensitized solar cells (117)(118)(119).…”

Preparation of PVC-NiFeCo3-Hybrid membranes for the Pervaporation Separation of Toluene-Heptane mixtures

“…Two weight loss stages were observed for NiFeCO 3 in the TGA curve, coinciding with two endothermic peaks in the DTA profiles. The first weight loss at 210°C was ascribed to the loss of physically absorbed and interlayer water and the second weight loss in the temperature range from 240 to 600°C could be attributed to removal of CO 2 from the inter-layer carbonate anions and water molecules from condensation of hydroxyl groups from the brucite-like layers [9,10], thus lead-to the destruction of hydrotalcite structure and the formation of mixed MII xMIIIy Ozoxides.…”