scholarly journals Sustainable Carbon as Efficient Support for Metal-Based Nanocatalyst: Applications in Energy Harvesting and Storage

Molecules ◽  
2020 ◽  
Vol 25 (14) ◽  
pp. 3123
Author(s):  
Mireia Buaki-Sogó ◽  
Leire Zubizarreta ◽  
Marta García-Pellicer ◽  
Alfredo Quijano-López

Sustainable activated carbon can be obtained from the pyrolysis/activation of biomass wastes coming from different origins. Carbon obtained in this way shows interesting properties, such as high surface area, electrical conductivity, thermal and chemical stability, and porosity. These characteristics among others, such as a tailored pore size distribution and the possibility of functionalization, lead to an increased use of activated carbons in catalysis. The use of activated carbons from biomass origins is a step forward in the development of more sustainable processes enhancing material recycling and reuse in the frame of a circular economy. In this article, a perspective of different heterogeneous catalysts based on sustainable activated carbon from biomass origins will be analyzed focusing on their properties and catalytic performance for determined energy-related applications. In this way, the article aims to give the reader a scope of the potential of these tailor-made sustainable materials as a support in heterogeneous catalysis and future developments needed to improve catalyst performance. The selected applications are those related with H2 energy and the production of biomethane for energy through CO2 methanation.

2017 ◽  
Vol 36 (3) ◽  
pp. 44-53
Author(s):  
G. D. Akpen ◽  
M. I. Aho ◽  
N. Baba

Activated carbon was prepared from the pods of Albizia saman for the purpose of converting the waste to wealth. The pods were thoroughly washed with water to remove any dirt, air- dried and cut into sizes of 2-4 cm. The prepared pods were then carbonised in a muffle furnace at temperatures of 4000C, 5000C, 6000C ,7000C and 8000C for 30 minutes. The same procedure was repeated for 60, 90, 120 and 150 minutes respectively. Activation was done using impregnationratios of 1:12, 1:6, 1:4, 1:3, and 1:2 respectively of ZnCl2 to carbonised Albizia saman pods by weight. The activated carbon was then dried in an oven at 1050C before crushing for sieve analysis. The following properties of the produced Albizia saman pod activated carbon (ASPAC) were determined: bulk density, carbon yield, surface area and ash, volatile matter and moisture contents. The highest surface area of 1479.29 m2/g was obtained at the optimum impregnation ratio, carbonization time and temperature of 1:6, 60 minutes and 5000C respectively. It was recommended that activated carbon should be prepared from Albizia saman pod with high potential for adsorption of pollutants given the high surface area obtained.Keywords: Albizia saman pod, activated carbon, carbonization, temperature, surface area


2016 ◽  
Vol 35 (6) ◽  
pp. 535-541 ◽  
Author(s):  
Hongying Xia ◽  
Jian Wu ◽  
Chandrasekar Srinivasakannan ◽  
Jinhui Peng ◽  
Libo Zhang

AbstractThe present work attempts to convert bamboo into a high surface area activated carbon via microwave heating. Different chemical activating agents such as KOH, NaOH, K2CO3 and Na2CO3 were utilized to identify a most suitable activating agent. Among the activating agents tested KOH was found to generate carbon with the highest porosity and surface area. The effect of KOH/C ratio on the porous nature of the activated carbon has been assessed. An optimal KOH/C ratio of 4 was identified, beyond which the surface area as well as the pore volume were found to decrease. At the optimized KOH/C ratio the surface area and the pore volume were estimated to be 3,441 m2/g and 2.093 ml/g, respectively, with the significant proportion of which being microporous (62.3%). Activated carbon prepared under the optimum conditions was further characterized using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). Activated carbons with so high surface area and pore volume are very rarely reported, which could be owed to the nature of the precursor and the optimal conditions of mixture ratio adopted in the present work.


2012 ◽  
Vol 66 (1) ◽  
pp. 179-184 ◽  
Author(s):  
Ş. Gül ◽  
O. Eren ◽  
Ş. Kır ◽  
Y. Önal

The objective of this study is to compare the performances of catalytic ozonation processes of two activated carbons prepared from olive stone (ACOS) and apricot stone (ACAS) with commercial ones (granular activated carbon-GAC and powder activated carbon-PAC) in degradation of reactive azo dye (Reactive Red 195). The optimum conditions (solution pH and amount of catalyst) were investigated by using absorbencies at 532, 220 and 280 nm wavelengths. Pore properties of the activated carbon (AC) such as BET surface area, pore volume, pore size distribution, and pore diameter were characterized by N2 adsorption. The highest BET surface area carbon (1,275 m2/g) was obtained from ACOS with a particle size of 2.29 nm. After 2 min of catalytic ozonation, decolorization performances of ACOS and ACAS (90.4 and 91.3%, respectively) were better than that of GAC and PAC (84.6 and 81.2%, respectively). Experimental results showed that production of porous ACs with high surface area from olive and apricot stones is feasible in Turkey.


2015 ◽  
Vol 13 (1) ◽  
Author(s):  
Eleni A. Deliyanni ◽  
George Z. Kyzas ◽  
Kostas S. Triantafyllidis ◽  
Kostas A. Matis

AbstractThis work is a systematic review of the literature over the past decade of the application of activated carbon (microporous or mesoporous) as adsorbents for the removal of heavy metals, focusing especially on lead (Pb) and arsenic (As) ions from the aqueous phase. Classical examples from our lab are also given. Activated carbon is known to provide a high surface area for adsorption. Generally, surface modification is typically required, such as oxidation, treatment with ammonia or even impregnation with ferric ion, etc. and the adsorbent material may originate from various sources. The pristine materials, after modification and those after batch-wise adsorption, were characterized by available techniques (BET analysis, Fourier transform infrared spectroscopy, scanning electron microscopy, thermal analyses, X-ray photoelectron spectroscopy). Adsorption isotherms, thermodynamics and kinetics of the process are also discussed. Selected studies from the literature are examined in comparison with other adsorbents. The role of chemistry in the metals adsorption/removal was investigated.


1992 ◽  
Vol 25 (1) ◽  
pp. 153-160 ◽  
Author(s):  
E. Diamadopoulos ◽  
P. Samaras ◽  
G. P. Sakellaropoulos

The objectives of this work were to relate the activated carbon properties to its adsorptive capacity. The activated carbon needed was produced in the lab from Greek lignite coal. Subsequently, adsorption studies were performed in order to evaluate the efficiency of the various activated carbons to remove toxic substances from water. Two organic substances were used. These were phenol and fulvic acid. Additionally, the adsorption of arsenic (V) was, also, investigated. It was found that the adsorptive capacity of the activated carbons depended primarily on the ash content and the compound. The capacity of the carbon to remove phenol, expressed as mg of phenol removed per g of activated carbon (carbon loading), decreased linearly as the amount of ash in the activated carbon increased. Ash-free activated carbons could adsorb 4 times as much phenol as the activated carbons with a high ash content. On the other hand, fulvic acid and arsenic adsorbed poorly on the ash-free activated carbons. Even for the high surface area activated carbons (over 1000 m2/g), the quantity of fulvic acid or arsenic adsorbed was significantly less than that exhibited by the high ash activated carbons (maximum surface area measured hardly exceeded 300 m2/g). As the amount of ash in the carbon increased, the carbon loading increased as well, up to a certain level, beyond which the amount of ash played no significant role. The beneficial role of ash was explained by the ability of the fulvic acid and arsenic to interact with metal oxides and metal ions, which constitute a significant fraction of the ash.


2020 ◽  
Vol 11 (3) ◽  
pp. 10265-10277

Activated carbons derived from rice husk pyrolysis (biochar) were prepared by chemical activation at different biochar/K2CO3 proportions in order to assess its capacity as adsorbent. The activated material was characterized by X-ray diffraction (DRX), Raman spectroscopy, scanning electron microscopy (SEM), the Brunauer, Emmet, and Teller (BET) method. The Barret, Joyner, and Halenda (BJH) method and functional density theory (DFT), presenting interesting texture properties, such as high surface area (BET 1850 m2 g-1) and microporosity, which allow its use as a sorbent phase in solid-phase extraction (SPE) of the main constituents of the aqueous pyrolysis phase. It was demonstrated that the activated carbon (RH-AC) adsorbs different compounds present in from rice husk pyrolysis wastewater through quantitative analysis by high-performance liquid chromatography with a diode-array detector (HPLC-DAD), presenting good linearity (R2 > 0.996) at 280 nm.


2014 ◽  
Vol 1644 ◽  
Author(s):  
Paul R. Armstrong ◽  
Zachary J. Morchesky ◽  
Dustin T. Hess ◽  
Kofi W. Adu ◽  
David. K. Essumang ◽  
...  

ABSTRACTWe present preliminary results on a processing protocol by chemical activation that transforms organic waste product such as coconut husk into high surface area activated carbon. Dried raw materials of the coconut husk were carbonized anaerobically into char. The char was impregnated with KOH of different ratios and were activated at 800°C and 900°C. The transmission electron microscope was used to acquire structural and morphological information of the activated carbon, and the surface area and porosity analysis were performed using Micromeritics ASAP 2020 analyzer. The activated carbons show both micropores and mesopores with specific surface area as high as 2900m2/g.


Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4658 ◽  
Author(s):  
Katarzyna Januszewicz ◽  
Anita Cymann-Sachajdak ◽  
Paweł Kazimierski ◽  
Marek Klein ◽  
Justyna Łuczak ◽  
...  

In this work, we present the preparation and characterization of biomass-derived activated carbon (AC) in view of its application as electrode material for electrochemical capacitors. Porous carbons are prepared by pyrolysis of chestnut seeds and subsequent activation of the obtained biochar. We investigate here two activation methods, namely, physical by CO2 and chemical using KOH. Morphology, structure and specific surface area (SSA) of synthesized activated carbons are investigated by Brunauer-Emmett-Teller (BET) technique and scanning electron microscopy (SEM). Electrochemical studies show a clear dependence between the activation method (influencing porosity and SSA of AC) and electric capacitance values as well as rate capability of investigated electrodes. It is shown that well-developed porosity and high surface area, achieved by the chemical activation process, result in outstanding electrochemical performance of the chestnut-derived porous carbons.


2016 ◽  
Vol 840 ◽  
pp. 348-352 ◽  
Author(s):  
Abdulkreem Alsultan ◽  
Asikin Mijan ◽  
Yun Hin Taufiq-Yap

Solid acid (heterogeneous) catalysts have a unique advantage in esterification and transesterification reactions which enhances the use of high acid value oil to be used as feedstock for synthesis of biodiesel. Activated carbon was prepared from walnut shell and activated in two step, first step is (thermal) physical activation calcination at 400 °C. Second step is chemical activation, the Ac were treated phosphoric acid in constant flow of nitrogen. The results obtained that the treated carbon show the amazing physicochemical properties (high surface area, high porosity and high acidity)


Author(s):  
Amira Alazmi ◽  
Sabina A. Nicolae ◽  
Pierpaolo Modugno ◽  
Bashir E. Hasanov ◽  
Maria M. Titirici ◽  
...  

The process of carbon dioxide capture and storage is seen as a critical strategy to mitigate the so-called greenhouse effect and the planetary climate changes associated with it. In this study, we investigated the CO2 adsorption capacity of various microporous carbon materials originating from palm date seeds (PDS) using green chemistry synthesis. The PDS was used as a precursor for the hydrochar and activated carbon (AC). Typically, by using the hydrothermal carbonization (HTC) process, we obtained a powder that was then subjected to an activation step using KOH, H3PO4 or CO2, thereby producing the activated HTC-PDS samples. Beyond their morphological and textural characteristics, we investigated the chemical composition and lattice ordering. Most PDS-derived powders have a high surface area (>1000 m2 g−1) and large micropore volume (>0.5 cm3 g−1). However, the defining characteristic for the maximal CO2 uptake (5.44 mmol g−1, by one of the alkaline activated samples) was the lattice restructuring that occurred. This work highlights the need to conduct structural and elemental analysis of carbon powders used as gas adsorbents and activated with chemicals that can produce graphite intercalation compounds.


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