Novel palladium nanoparticles supported on mesoporous natural phosphate: Catalytic ability for the preparation of aromatic hydrocarbons from natural terpenes

Abstract

Various ratios of palladium nanoparticles supported on mesoporous natural phosphate (Pd@NP) were prepared using the wetness impregnation method. The prepared catalysts were characterized by IR, XRD, CV, SEM, EDX, XRF, TEM and BET analysis. The reduction and preparation of the palladium nanoparticles afford a crystallite size of 10.88 nm. The performance of the synthesized catalyst was investigated in the solvent-free dehydroaromatization of α-, βand γ-himachalene mixture from Cedrus atlantica oil as a model substrate. In order to achieve an efficient and selective catalysis, the catalytic dehydroaromatization of various terpenes such as limonene, limonaketone, carvone, carveol and perillyl alcohol was studied. The Pd@NP catalyst performed a high catalytic activity, selectivity and recyclability in the terpenes dehydroaromatization reaction.

Catalytic dehydrogenation of natural terpenes via CuPd alloy nanoparticles generated on mesoporous graphitic carbon nitride

“…In addition, the dehydrogenation of limonaketone needs to be carried out at higher temperature. [ 16 ] Hence, the as‐prepared nanocatalysts Cu 50 Pd 50 /m‐gCN with a gradual decrease in Pd ratio shows a high activity, selectivity, and recyclability toward the dehydrogenation of natural terpenes under mild conditions, especially at lower and easy operated temperature, compared to the previously reported catalytic systems (Table S2).…”

“…Among the studied terpenes, dehydrogenation of himachalenes or dipentenes for the preparation of ar‐himachalene or p‐cymene are widely reported in the literature. [ 16 ] Regarding the dehydrogenation of himachalenes, different agents or catalysts were used for this reaction such as: lithium, [ 43 ] selenium, [ 44,45 ] chloranile, [ 46 ] Pd/C, [ 47 ] Raney nickel, [ 48 ] bromine, [ 49 ] DDQ, [ 50 ] and more recently palladium nanoparticles supported on mesoporous natural phosphate (Pd@NP) nanocatalysts. [ 15 ] In addition, the Pd@NP nanocatalysts were more efficient compared to the commercial heterogeneous catalysts (Pd/C and Raney nickel) as shown in Table S1.…”

“…[39] Therefore, terpenes can be used as raw materials in the synthesis of many of the hydrocarbon compounds commonly used in the industry and currently obtained from petroleumbased sources. [16] To date, it has been observed that the conversion reactions of terpenes are mostly conducted by using homogeneous catalysts and that the transformation reactions performed in the presence of heterogeneous catalysts are very limited. [40,41] As most of naturally occurring products, natural terpenic olefins expose some allyl, vinyl or isopropenyl groups as part of their structures for further functionalization.…”

Cucurbit[6]uril supported β-Ni(OH)2 nanoparticles as a heterogeneous catalyst for the synthesis of quinazolines via acceptorless dehydrogenative coupling of alcohols with nitriles

“…62,63,65 The use of a heterogeneous support not only prevents the agglomeration but also facilitates a uniform dispersion of NPs. [66][67][68][69][70] Recently, heterogeneous catalysts based on supported nanoparticles and heterogenization of homogeneous systems have become efficient and selective catalysts for a series of organic reactions. [71][72][73] They are preferred due to their robustness and lower operational cost, and easier recovery from the reaction mixture allowing chemical processes to be streamlined.…”

“…62,63,65 The use of a heterogeneous support not only prevents the agglomeration but also facilitates a uniform dispersion of NPs. 66–70…”