Pyrolysis Degradation of Cellulose over Highly Effective ZnO and ZnO−CuO Nanocatalysts

Abstract

Pyrolysis of lignocellulosic biomass with the use of appropriative catalysts can lead to the production of high yields of fuelsbio-oils. Here, zinc oxide -copper oxide (ZnOÀ CuO) nanocatalysts were synthesized by solvothermal synthesis. Highangle annular dark-field imaging scanning transmission electron microscopy (HAADF-STEM), high-resolution transmission electron microscopy (HRTEM), and energy-dispersive X-ray spectroscopy (EDXS) results suggested that ZnOÀ CuO nanoparticles (D = 23 � 5 nm) exhibit porous nanostructure. The pyrolytic degradation of cellulose using pyrolysis-gas chromatography-mass spectrometry (Py-GC/MS) unit has been studied over ZnO and ZnOÀ CuO nanocatalysts at the temperature range 400-800°C. The activation energy of ZnOÀ CuO (67.21 and 70.04 kJ/mol) was lower by 30 kJ/mol from the activation energy of clean ZnO and the calculated rate constants showed that the cellulose pyrolytic reaction is faster using ZnOÀ CuO catalyst. Nanoporous ZnOÀ CuO shifted the products maximum towards lower temperatures (< 500°C), reduced the content of aldehydes at 400-500°C and enhanced the overall product composition and bio-oil yield. Porous structure of ZnO nanocatalysts had a significant effect on the product selectivity and reaction mechanism of cellulose pyrolysis.

Green Synthesis of a CuO–ZnO Nanocomposite for Efficient Photodegradation of Methylene Blue and Reduction of 4-Nitrophenol

“…CuO–ZnO NCs can be fabricated by various methods including precipitation, sol–gel, solvothermal, electrospinning, photodeposition, microwave-assisted, electrochemical, thermal decomposition, and spray pyrolysis . Among these methods, a microwave-assisted method has several benefits in comparison to conventional heating methods, such as fast reactions, uniform particle size distribution, high yield, and highly pure nanomaterials .…”

Effect of Temperature and MgCl2 Concentration on the Catalytic Pyrolysis of Malt Waste Using Response Surface Methodology

“…The peak assigned to CÀ H stretching (2875-2960 cm À 1 ) corresponds to aliphatic functional groups present in compounds like alkanes and akenes, which are also stronger in the raw material than in the biochar. Equation (10) describes the prediction equation (R 2 = 0.931) for the ratio between the integrated areas of the CÀ H bond stretching from the biochar and from the raw material (R char ðCÀ HÞS ) as a function of the coded factors X 1 (T) and X 2 (F A ). A mean reduction of 62.2 % was observed in the peak area of biochar compared with the MW.…”

“…[3,4] This process is normally carried out in the total or partial absence of oxygen, at a temperature range of 400-600 °C. [5] Many industrial wastes, such as plastic waste, [6,7] spent tire, [8] tetra pak residue, [9] cellulose, [10,11] lignin, [12] sugarcane bagasse, [13][14][15] coffee residues, [16,17] corncob, [18] fruit residue, [19] oilseed shells, [20] microalgae, [21,22] seeds [23,24] and pine wood, [25] among others, have been evaluated as sources for the pyrolysis process.…”

Croton macrostachyus Leaf Extract-Mediated Green Synthesis of ZnO Nanoparticles and ZnO/CuO Nanocomposites for the Enhanced Photodegradation of Methylene Blue Dye with the COMSOL Simulation Model

“…This high activity was attributed to the enhanced photogenerated charge carrier separation and transfer caused by the band coupling between ZnO and CuO. 22 The preparation of ZnO NPs as well as ZnO-based nanocomposites (NCs) has been carried out by various wellknown methods such as sol−gel, 23 hydrothermal and solvothermal, 24,25 precipitation, 26 electrochemical, 27,28 thermal decomposition, 15 microwave-assisted, 29 and spray pyrolysis. 30 However, the above-mentioned synthesis techniques are expensive, complex, and toxic to the environment due to the association of various hazardous chemicals 31 as reducing and stabilizing agents.…”