Research

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16 pages, 5139 KiB

Open AccessArticle

Porous Biochar Supported Transition Metal Phosphide Catalysts for Hydrocracking of Palm Oil to Bio-Jet Fuel

by Napat Kaewtrakulchai, Araya Smuthkochorn, Kanit Manatura, Gasidit Panomsuwan, Masayoshi Fuji and Apiluck Eiad-Ua

Materials 2022, 15(19), 6584; https://doi.org/10.3390/ma15196584 - 22 Sep 2022

Cited by 5 | Viewed by 1828

Abstract

The upgrading of plant-based oils to liquid transportation fuels through the hydrotreating process has become the most attractive and promising technical pathway for producing biofuels. This work produced bio-jet fuel (C₉–C₁₄ hydrocarbons) from palm olein oil through hydrocracking over varied [...] Read more.

The upgrading of plant-based oils to liquid transportation fuels through the hydrotreating process has become the most attractive and promising technical pathway for producing biofuels. This work produced bio-jet fuel (C₉–C₁₄ hydrocarbons) from palm olein oil through hydrocracking over varied metal phosphide supported on porous biochar catalysts. Relative metal phosphide catalysts were investigated for the highest performance for bio-jet fuel production. The palm oil’s fiber-derived porous biochar (PFC) revealed its high potential as a catalyst supporter. A series of PFC-supported cobalt, nickel, iron, and molybdenum metal phosphides (Co-P/PFC, Ni-P/PFC, Fe-P/PFC, and Mo-P/PFC) catalysts with a metal-loading content of 10 wt.% were synthesized by wet-impregnation and a reduction process. The performance of the prepared catalysts was tested for palm oil hydrocracking in a trickle-bed continuous flow reactor under fixed conditions; a reaction temperature of 420 °C, LHSV of 1 h⁻¹, and H₂ pressure of 50 bar was found. The Fe-P/PFC catalyst represented the highest hydrocracking performance based on 100% conversion with 94.6% bio-jet selectivity due to its higher active phase dispersion along with high acidity, which is higher than other synthesized catalysts. Moreover, the Fe-P/PFC catalyst was found to be the most selective to C₉ (35.4%) and C₁₀ (37.6%) hydrocarbons. Full article

(This article belongs to the Special Issue Nanostructured Materials for Energy Applications)

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20 pages, 3790 KiB

Open AccessArticle

Characteristics of Methyl Cellulose Based Solid Polymer Electrolyte Inserted with Potassium Thiocyanate as K⁺ Cation Provider: Structural and Electrical Studies

by Shujahadeen B. Aziz, Elham M. A. Dannoun, Ari A. Abdalrahman, Rebar T. Abdulwahid, Sameerah I. Al-Saeedi, Mohamad A. Brza, Muaffaq M. Nofal, Ranjdar M. Abdullah, Jihad M. Hadi and Wrya O. Karim

Materials 2022, 15(16), 5579; https://doi.org/10.3390/ma15165579 - 14 Aug 2022

Cited by 5 | Viewed by 3904

Abstract

The attention to a stable and ionic conductive electrolyte is driven by the limitations of liquid electrolytes, particularly evaporation and leakage, which restrain their widespread use for electrochemical device applications. Solid polymer electrolyte (SPE) is considered to be a potential alternative since it [...] Read more.

The attention to a stable and ionic conductive electrolyte is driven by the limitations of liquid electrolytes, particularly evaporation and leakage, which restrain their widespread use for electrochemical device applications. Solid polymer electrolyte (SPE) is considered to be a potential alternative since it possesses high safety compared to its counterparts. However, it still suffers from low device efficiency due to an incomplete understanding of the mechanism of ion transport parameters. Here, we present a simple in situ solution casting method for the production of polymer-based electrolytes using abundantly available methylcellulose (MC) doped at different weight percentages of potassium thiocyanate (KSCN) salt. Fourier transform infrared (FTIR), and electrochemical impedance spectroscopy (EIS) methods were used to characterize the prepared samples. Based on EIS simulation and FTIR deconvolution associated with the SCN anion peak, various ion transport parameters were determined. The host MC medium and KSCN salt have a strong interaction, which was evident from both peak shifting and intensity alteration of FTIR spectra. From the EIS modeling, desired electric circuits correlated with ion movement and chain polarization were drawn. The highest ionic conductivity of 1.54 × 10⁻⁷ S cm⁻¹ is determined from the fitted EIS curve for the film doped with 30 wt.% of KSCN salt. From the FTIR deconvoluted peak, free ions, ions in contact with one another, and ion aggregates were separated. The extracted ion transport parameters from the EIS method and FTIR spectra of the SCN anion band confirm that both increased carrier concentration and their mobility were crucial in improving the overall conductivity of the electrolyte. The dielectric investigations were further used to understand the conductivity of the films. High dielectric constants were observed at low frequencies for all MC:KSCN systems. The dispersion with a high dielectric constant in the low-frequency band is ascribed to the dielectric polarization. The wide shift of M″ peak towards the high frequency was evidenced by the MC-based electrolyte impregnated with 30 wt.% of KSCN salt, revealing the improved ionic movement assisted with chain segmental motion. The AC conductivity pattern was influenced by salt concentration. Full article

(This article belongs to the Special Issue Nanostructured Materials for Energy Applications)

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16 pages, 3082 KiB

Open AccessArticle

Assessment of Woodcrete Using Destructive and Non-Destructive Test Methods

by Ashraf A.M. Fadiel, Taher Abu-Lebdeh and Florian Ion T. Petrescu

Materials 2022, 15(9), 3066; https://doi.org/10.3390/ma15093066 - 22 Apr 2022

Cited by 10 | Viewed by 2200

Abstract

Utilizing solid wastes and industrial by-products as a partial replacement for raw materials has become an acceptable practice among researchers and scientists in the civil engineering field. Sawdust and wood shavings are not an exception; they are being used in concrete as a [...] Read more.

Utilizing solid wastes and industrial by-products as a partial replacement for raw materials has become an acceptable practice among researchers and scientists in the civil engineering field. Sawdust and wood shavings are not an exception; they are being used in concrete as a partial or total replacement for some of its constituents. The main goal of this research is to establish a relation between destructive and non-destructive testing for concrete containing wood shavings as a partial replacement of sand (woodcrete). With this type of material existing, thus the need to understand the behavior of such material becomes urgent and evokes the need to ease the process of the assessment and the evaluation of such materials and therefore provide more understanding of its behavior. In addition to the conventional concrete mix, five mixes of woodcrete were made by replacing fine aggregate by volume with wood shavings at different replacement levels varied from 5% to 50%. Cubic samples were tested at the age of 90 days using nondestructive tests (NDT), namely, rebound hammer test and ultrasonic pulse velocity test. Then, the specimens were tested using a conventional compressive test using a universal compression testing machine. Statistical analysis was performed to establish empirical relations between destructive and non-destructive results. The dynamic modulus of elasticity was calculated, and some formulas to estimate the (compressive) strength of woodcrete using NDT results were proposed and tested against experimental results and showed acceptable results. Full article

(This article belongs to the Special Issue Nanostructured Materials for Energy Applications)

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17 pages, 3317 KiB

Open AccessArticle

Performance of Nanocomposites of a Phase Change Material Formed by the Dispersion of MWCNT/TiO₂ for Thermal Energy Storage Applications

by Maha AlOtaibi, Mohammed Alsuhybani, Maha Khayyat and Bandar AlOtaibi

Materials 2022, 15(9), 3063; https://doi.org/10.3390/ma15093063 - 22 Apr 2022

Cited by 5 | Viewed by 1422

Abstract

Thermal energy storage technology is an important topic, as it enables renewable energy technology to be available 24/7 and under different weather conditions. Phase changing materials (PCM) are key players in thermal energy storage, being the most economic among those available with adjustable [...] Read more.

Thermal energy storage technology is an important topic, as it enables renewable energy technology to be available 24/7 and under different weather conditions. Phase changing materials (PCM) are key players in thermal energy storage, being the most economic among those available with adjustable thermal properties. Paraffin wax (PW) is one of the best materials used in industrial processes to enhance thermal storage. However, the low thermal conductivity of PW prevents its thermal application. In this study, we successfully modified PW based on multi-walled carbon nanotubes (MWCNT) with different concentrations of TiO₂—3, 5 and 7 wt.%. The morphology of PCM and its relationship with the chemical structure and stability were characterized using scanning electron microscopy (SEM), Fourier transform infrared (FTIR) and Thermogravimetric analysis (TGA). As a result, the composites achieved a highest latent heat enthalpy of 176 J/g, in addition to enhanced thermal stability after 15 thermal cycles, and reliability, with a slight change in latent heat observed when using a differential scanning calorimeter (DSC). The thermal conductivity of the composites could significantly be enhanced by 100%. Compared to pure paraffin, the PCM composites developed in this study exhibited an excellent preference for thermal energy storage and possessed low cost, high reliability, and phase change properties. Full article

(This article belongs to the Special Issue Nanostructured Materials for Energy Applications)

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11 pages, 3887 KiB

Open AccessArticle

MXene Enhanced the Electromechanical Performance of a Nafion-Based Actuator

by Xiaoming Tang, Ziyi Zhou, Yuehang Jiang, Qian Wang, Qi Sun, Lei Zu, Xing Gao, Huiqin Lian, Minhua Cao and Xiuguo Cui

Materials 2022, 15(8), 2833; https://doi.org/10.3390/ma15082833 - 12 Apr 2022

Cited by 4 | Viewed by 1673

Abstract

Ionic electroactive polymer-based actuators have attracted much attention due to their low potential stimuli. In this work, MXene–Nafion composite actuators were fabricated, and the actuation performances were tested. The morphology of the as-made MXene–Nafion composite showed that the composite membrane was homogeneous, with [...] Read more.

Ionic electroactive polymer-based actuators have attracted much attention due to their low potential stimuli. In this work, MXene–Nafion composite actuators were fabricated, and the actuation performances were tested. The morphology of the as-made MXene–Nafion composite showed that the composite membrane was homogeneous, with an MXene doping level up to 5 wt%. In addition, the results of blocked force, response speed, and durability demonstrated that the actuation behavior of the composite-based actuator was enhanced due to the efficient dispersion of the two-dimensional nanofiller MXene. In addition, the blocking force of the composite actuator with a doping level of 0.5 wt% was about 6 times that of the pure Nafion without back-relaxation and durability degradation during the testing period. Full article

(This article belongs to the Special Issue Nanostructured Materials for Energy Applications)

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Review

Jump to: Research

14 pages, 4956 KiB

Open AccessReview

Recent Progress in Double-Layer Honeycomb Structure: A New Type of Two-Dimensional Material

by Ming-Yu Ma, Dong Han, Nian-Ke Chen, Dan Wang and Xian-Bin Li

Materials 2022, 15(21), 7715; https://doi.org/10.3390/ma15217715 - 02 Nov 2022

Cited by 4 | Viewed by 1886

Abstract

Two-dimensional (2D) materials are no doubt the most widely studied nanomaterials in the past decade. Most recently, a new type of 2D material named the double-layer honeycomb (DLHC) structure opened a door to achieving a series of 2D materials from traditional semiconductors. However, [...] Read more.

Two-dimensional (2D) materials are no doubt the most widely studied nanomaterials in the past decade. Most recently, a new type of 2D material named the double-layer honeycomb (DLHC) structure opened a door to achieving a series of 2D materials from traditional semiconductors. However, as a newly developed material, there still lacks a timely understanding of its structure, property, applications, and underlying mechanisms. In this review, we discuss the structural stability and experimental validation of this 2D material, and systematically summarize the properties and applications including the electronic structures, topological properties, optical properties, defect engineering, and heterojunctions. It was concluded that the DLHC can be a universal configuration applying to III–V, II–VI, and I–VII semiconductors. Moreover, these DLHC materials indeed have exotic properties such as being excitonic/topological insulators. The successful fabrication of DLHC materials further demonstrates it is a promising topic. Finally, we summarize several issues to be addressed in the future, including further experimental validation, defect engineering, heterojunction engineering, and strain engineering. We hope this review can help the community to better understand the DLHC materials timely and inspire their applications in the future. Full article

(This article belongs to the Special Issue Nanostructured Materials for Energy Applications)

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29 pages, 5653 KiB

Open AccessReview

Metal–Organic Frameworks (MOFs) Derived Materials Used in Zn–Air Battery

by Dongmei Song, Changgang Hu, Zijian Gao, Bo Yang, Qingxia Li, Xinxing Zhan, Xin Tong and Juan Tian

Materials 2022, 15(17), 5837; https://doi.org/10.3390/ma15175837 - 24 Aug 2022

Cited by 9 | Viewed by 2959

Abstract

It is necessary to develop new energy technologies because of serious environmental problems. As one of the most promising electrochemical energy conversion and storage devices, the Zn–air battery has attracted extensive research in recent years due to the advantages of abundant resources, low [...] Read more.

It is necessary to develop new energy technologies because of serious environmental problems. As one of the most promising electrochemical energy conversion and storage devices, the Zn–air battery has attracted extensive research in recent years due to the advantages of abundant resources, low price, high energy density, and high reduction potential. However, the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) of Zn–air battery during discharge and charge have complicated multi-electron transfer processes with slow reaction kinetics. It is important to develop efficient and stable oxygen electrocatalysts. At present, single-function catalysts such as Pt/C, RuO₂, and IrO₂ are regarded as the benchmark catalysts for ORR and OER, respectively. However, the large-scale application of Zn–air battery is limited by the few sources of the precious metal catalysts, as well as their high costs, and poor long-term stability. Therefore, designing bifunctional electrocatalysts with excellent activity and stability using resource-rich non-noble metals is the key to improving ORR/OER reaction kinetics and promoting the commercial application of the Zn–air battery. Metal–organic framework (MOF) is a kind of porous crystal material composed of metal ions/clusters connected by organic ligands, which has the characteristics of adjustable porosity, highly ordered pore structure, low crystal density, and large specific surface area. MOFs and their derivatives show remarkable performance in promoting oxygen reaction, and are a promising candidate material for oxygen electrocatalysts. Herein, this review summarizes the latest progress in advanced MOF-derived materials such as oxygen electrocatalysts in a Zn–air battery. Firstly, the composition and working principle of the Zn–air battery are introduced. Then, the related reaction mechanism of ORR/OER is briefly described. After that, the latest developments in ORR/OER electrocatalysts for Zn–air batteries are introduced in detail from two aspects: (i) non-precious metal catalysts (NPMC) derived from MOF materials, including single transition metals and bimetallic catalysts with Co, Fe, Mn, Cu, etc.; (ii) metal-free catalysts derived from MOF materials, including heteroatom-doped MOF materials and MOF/graphene oxide (GO) composite materials. At the end of the paper, we also put forward the challenges and prospects of designing bifunctional oxygen electrocatalysts with high activity and stability derived from MOF materials for Zn–air battery. Full article

(This article belongs to the Special Issue Nanostructured Materials for Energy Applications)

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47 pages, 9444 KiB

Open AccessReview

One-Dimensional (1D) Nanostructured Materials for Energy Applications

by Abniel Machín, Kenneth Fontánez, Juan C. Arango, Dayna Ortiz, Jimmy De León, Sergio Pinilla, Valeria Nicolosi, Florian I. Petrescu, Carmen Morant and Francisco Márquez

Materials 2021, 14(10), 2609; https://doi.org/10.3390/ma14102609 - 17 May 2021

Cited by 52 | Viewed by 7584

Abstract

At present, the world is at the peak of production of traditional fossil fuels. Much of the resources that humanity has been consuming (oil, coal, and natural gas) are coming to an end. The human being faces a future that must necessarily go [...] Read more.

At present, the world is at the peak of production of traditional fossil fuels. Much of the resources that humanity has been consuming (oil, coal, and natural gas) are coming to an end. The human being faces a future that must necessarily go through a paradigm shift, which includes a progressive movement towards increasingly less polluting and energetically viable resources. In this sense, nanotechnology has a transcendental role in this change. For decades, new materials capable of being used in energy processes have been synthesized, which undoubtedly will be the cornerstone of the future development of the planet. In this review, we report on the current progress in the synthesis and use of one-dimensional (1D) nanostructured materials (specifically nanowires, nanofibers, nanotubes, and nanorods), with compositions based on oxides, nitrides, or metals, for applications related to energy. Due to its extraordinary surface–volume relationship, tunable thermal and transport properties, and its high surface area, these 1D nanostructures have become fundamental elements for the development of energy processes. The most relevant 1D nanomaterials, their different synthesis procedures, and useful methods for assembling 1D nanostructures in functional devices will be presented. Applications in relevant topics such as optoelectronic and photochemical devices, hydrogen production, or energy storage, among others, will be discussed. The present review concludes with a forecast on the directions towards which future research could be directed on this class of nanostructured materials. Full article

(This article belongs to the Special Issue Nanostructured Materials for Energy Applications)

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