Turkish perlite supported nickel oxide as the heterogeneous acid catalyst for a series of Claisen–Schmidt condensation reactions

Abstract

Potentially active and eco-friendly solid acid catalysts have been synthesized by loading different weight percentages (10, 15, and 50) of nickel oxide on thermally activated Turkish perlite through the deposition-precipitation method. Structural features of prepared catalysts were analyzed using BET surface area analysis, X-ray diffraction, SEM, SEM-EDX, TEM, FT-IR, pyridine adsorbed FT-IR, UV-Vis DRS, and TGA techniques. Pyridine adsorbed FT-IR analysis confirmed the presence of the optimum amount of Bronsted acidic sites in a catalyst having 15 wt. % loading of nickel oxide which was tested for catalyzing a series of Claisen-Schmidt condensation of cyclohexanone and aromatic aldehydes to produce good isolated yield (90-93%) of 2,6bis(substituted benzylidene)cyclohexanones, significantly used in anti-tumor and cytotoxic activities. The high catalytic efficiency of the chosen catalyst remains almost 2 intact up to six reaction cycles. On higher wt. % loading of nickel oxide, crystallite size increases along with agglomeration of larger nickel oxide particles on catalyst surface resulting in pore blockage and poor catalytic activity. Loading of NiO on the surface of thermally activated Turkish perlite was confirmed by SEM-EDX analysis and TEM observations show that the particle size of the preferred catalyst was less than 50 nm.Based on results drawn from XRD, FT-IR, pyridine adsorbed FT-IR, UV-Vis DRS studies, model structures were proposed for Turkish perlite and all prepared catalysts.During this work, the catalytic potential of the preferred catalyst was compared with other previously reported catalysts and it showed appreciable results. The formed products were further confirmed by their melting point and 1 H-NMR analysis.

Perlite Supported Cobalt Oxide Catalyst for a Series of Liquid‐Phase Esterification Reactions

“…The broad X‐ray diffraction patterns of perlite and TAP ( Figure ) were appropriately explained in our recent work. [ 1 ] The XRD image of the Co‐TAP catalyst ( Figure ) shows the presence of a broad band at 2 θ around 23° indicating the presence of amorphous silica in the catalyst, also seen in the XRD images of perlite and TAP. The other main, small diffraction peaks at 2 θ = 31.5°, 37.2°, 59.7°, and 65.5° are results of the diffraction from (111), (311), (222), (422), and (440) planes of face‐centered cubic (FCC) CoO crystals, respectively, indicating the presence of Co 3 O 4 crystallites.…”

“…So-obtained products were confirmed by qualitative laboratory tests. Isolated yield % of reaction products were calculated by using the following formula: Isolated yield % of products = 100 × Experimental yield of products (in g) Theoretical yield of products (in g) (1)…”

“…Perlite, highly porous, layered, lightweight, natural amorphous volcanic glass formed by the cooling of volcanic outbursts, composed of onion with several circular layers containing silica, alumina, sodium, and potassium oxides as chief components. [ 1 ] When it is treated thermally at a very high temperature, that is, more than 800°C, hydrated water molecules embedded inside these circular layers vanished, consequently, an uncommon volume expansion takes place up to eight to 20 times of its initial volume. This results in the formation of chemically inert, floatable, nonpoisonous particles with low density in the range of 30–150 kg m –3 , average particle diameter between 0 and 3 mm, [ 2 ] and specific surface area around 1.7 m 2 g –1 .…”

“…[ 27 ] Previously our research group has synthesized effective solid catalysts based on coal‐generated solid waste, fly ash, [ 28–32 ] and perlite. [ 1 ] Since esterification is a very useful reaction with valuable industrial prospects but at mass scale it takes place via conventional methods. On the other hand, sonication and microwave‐assisted reaction media shorten the reaction duration, enhance reaction kinetics, suppress the formation of undesired products, and make the whole process cost‐effective and greener.…”

Vapor Phase Alkylation of Isomeric Cresols with Tert-Butyl Alcohol over Perlite Supported Sulfated Zirconia Catalyst

“…Hence, in recent years, perlite was also utilized as an effective substrate in the synthesis of heterogeneous acid catalysts in different organic transformations, i.e., Fenton reactions of organic compounds [9], the production of aryl/alkyl methane [10], photocatalysis [11], synthesis of xanthenes [12], transesterification reactions [13], condensation reactions [14], the degradation of azo-dyes [15], hydrogenation reactions [16], etc. We recently reported the synthesis of perlite supported catalysts and their catalytic activities in a series of different types of condensation and esterification reactions [17][18][19]. Due to its rough surface and low density, relatively low price, stability in various reaction media, high thermal, chemical, and mechanical stability, perlite acts as suitable support in the development of potential heterogeneous catalysts for catalyzing vapor phase organic transformations at an industrial scale and can replace solid catalysts traditionally used in this field.…”