Catalytic Hydrodeoxygenation of Fatty Acids for Biodiesel Production

This paper is devoted to the production of second generation biodiesel via catalytic hydrodeoxygenation of fatty acids. Pd/C catalysts with different metal loading were used. The palladium catalysts were characterized using low-temperature nitrogen physisorption and X-ray photoelectron spectroscopy. It was revealed that the most active and selective catalyst was 1%-Pd/C which allowed reaching up 97.5% of selectivity (regarding to n-heptadecane) at 100% conversion of substrate. Moreover, the chosen catalyst is more preferable according to lower metal content that leads the decrease of the process cost. The analysis of the catalysts showed that 1%-Pd/C had the highest specific surface area compared with 5%-Pd/C. Copyright © 2016 BCREC GROUP. All rights reservedReceived: 31st July 2015; Revised: 9th December 2015; Accepted: 30th December 2015How to Cite: Stepacheva, A.A., Sapunov, V.N., Sulman, E.M., Nikoshvili, L.Z., Sulman, M.G., Sidorov, A.I., Demidenko, G.N., Matveeva, V.G. (2016). Catalytic Hydrodeoxygenation of Fatty Acids for Biodiesel Production. Bulletin of Chemical Reaction Engineering & Catalysis, 11 (2): 125-132 (doi:10.9767/bcrec.11.2.538.125-132)Permalink/DOI: http://dx.doi.org/10.9767/bcrec.11.2.538.125-132Article Metrics: (click on the button below to see citations in Scopus)

Pd-Nanoparticles Confined Within Hollow Polymeric Framework as Effective Catalysts for the Synthesis of Fine Chemicals

Encapsulation of metal nanoclusters in porous solid polymer materials is a promising approach to combine the outstanding properties of both, heterogeneous and homogeneous catalysts. We report heterogeneous nano-engineered catalysts containing Pd-nanoparticles (NPs) confined within highly-porous hollow polymeric framework of hyper cross-linked polystyrene (HPS). HPS with different surface functionalities (amine vs. sulfonate) were used for impregnation by Pd precursors of different nature and followed by a variety of catalyst post-treatments. The catalysts have been tested in two model key reactions for the synthesis of fine chemicals: selective hydrogenation of 2-methyl-3-butyne-2-ol to 2-methyl-3-butene-2-ol (MBE) and Suzuki cross-coupling of 4-bromoanisole with phenylboronic acid. Optimization of the Pd/HPS preparation and reaction conditions allowed attaining high selectivity (similar to 99 %) to target MBE at close to full conversion. For Suzuki cross-coupling more than 90 % yield of coupling product was obtained under mild reaction conditions and the absence of phase transfer agent. Our results demonstrate the potential of HPS as a suitable support for tailoring metal NPs properties and circumvent undesirable metal leaching

Cellulose Conversion Into Hexitols and Glycols in Water: Recent Advances in Catalyst Development

Conversion of biomass cellulose to value-added chemicals and fuels is one of the most important advances of green chemistry stimulated by needs of industry. Here we discuss modern trends in the development of catalysts for two processes of cellulose conversion: (i) hydrolytic hydrogenation with the formation of hexitols and (ii) hydrogenolysis, leading to glycols. The promising strategies include the use of subcritical water which facilitates hydrolysis, bifunctional catalysts which catalyze not only hydrogenation, but also hydrolysis, retro-aldol condensation, and isomerization, and pretreatment (milling) of cellulose together with catalysts to allow an intimate contact between the reaction components. An important development is the replacement of noble metals in the catalysts with earth-abundant metals, bringing down the catalyst costs, and improving the environmental impact

Recent Progress in Chitosan-Containing Composite Materials for Sustainable Approaches to Adsorption and Catalysis

In recent years, composite materials including organic–inorganic systems have drawn special attention due to their enhanced properties such as adsorbents and heterogeneous catalysts. At the same time, large-scale production of environmentally benign functionalized biopolymers, such as chitosan (CS), allows for constantly developing new materials, since CS reveals remarkable properties as a stabilizing agent for metal-containing compounds and enzymes and as an adsorbent of organic molecules. This review is focused on CS-based materials and on the composite systems including CS-oxide and CS-metal composites in particular for application as adsorbents and supports for catalytically active metal nanoparticles and enzymes

Comparison of methanol to gasoline conversion in one-step, two-step, and cascade mode in the presence of H-ZSM-5 zeolite

In this report, three technological modes for methanol-to-gasoline reaction in the presence of H-ZSM-5 catalyst are compared: (i) direct methanol transformation to hydrocarbons; (ii) two-step (methanol-dimethyl ether-hydrocarbons); and (iii) cascade pathway. Light hydrocarbon gases (methane, ethylene, propylene, and isobutene) and liquid aromatic hydrocarbons (benzene, toluene, xylene, cresol, durol, naphthalene, methylnaphthalene, ethyl naphthalene, isopropyl naphthalene, methyl isopropyl naphthalene, etc.) were found to be the main reaction products. The experimental results showed that the classical two-step methanol to gasoline (MTG) process nowadays remains the most effective for gasoline-range hydrocarbons production, while one-step and cascade schemes require further investigation and the development of reactor systems as well as the operating conditions. The product distribution of MTG synthesis after 120 h on stream in the case of two-step mode was found to be the following: liquid C6–C8 hydrocarbons – 23%; C1–C5 gaseous products – 65%; heavy C9–C12 hydrocarbons – 10%

Magnetically Recoverable Nanoparticulate Catalysts for Cross-Coupling Reactions: The Dendritic Support Influences the Catalytic Performance

Carbon-carbon cross-coupling reactions are among the most important synthetic tools for the preparation of pharmaceuticals and bioactive compounds. However, these reactions are normally carried out using copper, phosphines, and/or amines, which are poisonous for pharmaceuticals. The use of nanocomposite catalysts holds promise for facilitating these reactions and making them more environmentally friendly. In the present work, the PEGylated (PEG stands for poly(ethylene glycol) pyridylphenylene dendrons immobilized on silica loaded with magnetic nanoparticles have been successfully employed for the stabilization of Pd2+ complexes and Pd nanoparticles. The catalyst developed showed excellent catalytic activity in copper-free Sonogashira and Heck cross-coupling reactions. The reactions proceeded smoothly in green solvents at low palladium loading, resulting in high yields of cross-coupling products (from 80% to 97%) within short reaction times. The presence of magnetic nanoparticles allows easy magnetic separation for repeated use without a noticeable decrease of catalytic activity due to the strong stabilization of Pd species by rigid and bulky dendritic ligands. The PEG dendron periphery makes the catalyst hydrophilic and better suited for green solvents. The minor drop in activity upon the catalyst reuse is explained by the formation of Pd nanoparticles from the Pd2+ species during the catalytic reaction. The magnetic separation and reuse of the nanocomposite catalyst reduces the cost of target products as well as energy and material consumption and diminishes residual contamination by the catalyst. These factors as well as the absence of copper in the catalyst makeup pave the way for future applications of such catalysts in cross-coupling reactions

Catalysts of Suzuki Cross-Coupling Based on Functionalized Hyper-cross-linked Polystyrene: Influence of Precursor Nature

This paper describes synthesis of Pd-containing catalysts of Suzuki cross-coupling based on amino-functionalized hyper-cross-linked polystyrene at variation of Pd precursor nature (PdCl2, PdCl2(CH3CN)(2), or PdCl2(PhCN)(2)). The investigation of the influence of palladium, oxidation state (Pd(II) or Pd(0)) and form (Pd-n dusters or Pd nanoparticles) on the rate of Suzuki cross-coupling of 4-bromoanisole and phenylboronic acid is discussed. Developed catalysts are shown to allow achieving, conversion of 4-bromoanisole higher than 98% under mild reaction conditions. Independently of the precursor nature, Pd(II) is mainly responsible for observed catalytic activity. However, preliminary reduction of catalysts with H-2 results in formation of a large number of Pd-n. clusters, the contribution of which in the Suzuki reaction becomes predominant

ZnO Particles Stabilized in Polymeric Matrix for Liquid-Phase Methanol Synthesis

ZnO supported on hypercrosslinked polystyrene was developed for liquid-phase methanol synthesis. The synthesized catalyst was characterized using the low-temperature nitrogen physisorption, TEM, XPS, XAS, and CO DRIFT methods. The analysis showed that the catalyst has a high specific surface area (720 m2/g) and is characterized by the micro-mesoporous structure typical of the polymer used. The active phase is represented by ZnO species with a hexagonal wurtzite structure. ZnO-HPS showed high activity, selectivity, and stability in liquid-phase methanol synthesis in comparison with the industrial catalyst. The activity of the proposed catalyst was found to be 1.64 times higher than that of the conventional Cu/ZnO/Al2O3

Mono- and Bimetallic Nanoparticles Stabilized by an Aromatic Polymeric Network for a Suzuki Cross-Coupling Reaction

This work addresses the Suzuki cross-coupling between 4-bromoanisole (BrAn) and phenylboronic acid (PBA) in an environmentally benign ethanol–water solvent catalysed by mono- (Pd) and bimetallic (PdAu, PdCu, PdZn) nanoparticles (NPs) stabilised within hyper-cross-linked polystyrene (HPS) bearing tertiary amino groups. Small Pd NPs of about 2 nm in diameters were formed and stabilized by HPS independently in the presence of other metals. High catalytic activity and complete conversion of BrAn was attained at low Pd loading. Introduction of Zn to the catalyst composition resulted in the formation of Pd/Zn/ZnO NPs, which demonstrated nearly double activity as compared to Pd/HPS. Bimetallic core-shell PdAu/HPS samples were 3-fold more active as compared to Pd/HPS. Both Pd/HPS and PdAu/HPS samples revealed promising stability confirmed by catalyst recycling in repeated reaction runs