Showing papers in "Energy & Fuels in 2021"
Cardiff University1, Universiti Brunei Darussalam2, Delft University of Technology3, German National Metrology Institute4, Technical University of Denmark5, University of Massachusetts Amherst6, University of Orléans7, National Autonomous University of Mexico8, University of Milan9, Cairo University10, Instituto Superior Técnico11
TL;DR: Ammonia has been considered as a candidate to power transport, produce energy, and support heating applications for decades, however, the particular characteristics of the molecule always made it a chemical with low, if any, benefit once compared to conventional fossil fuels as discussed by the authors.
Abstract: Ammonia, a molecule that is gaining more interest as a fueling vector, has been considered as a candidate to power transport, produce energy, and support heating applications for decades. However, the particular characteristics of the molecule always made it a chemical with low, if any, benefit once compared to conventional fossil fuels. Still, the current need to decarbonize our economy makes the search of new methods crucial to use chemicals, such as ammonia, that can be produced and employed without incurring in the emission of carbon oxides. Therefore, current efforts in this field are leading scientists, industries, and governments to seriously invest efforts in the development of holistic solutions capable of making ammonia a viable fuel for the transition toward a clean future. On that basis, this review has approached the subject gathering inputs from scientists actively working on the topic. The review starts from the importance of ammonia as an energy vector, moving through all of the steps in the production, distribution, utilization, safety, legal considerations, and economic aspects of the use of such a molecule to support the future energy mix. Fundamentals of combustion and practical cases for the recovery of energy of ammonia are also addressed, thus providing a complete view of what potentially could become a vector of crucial importance to the mitigation of carbon emissions. Different from other works, this review seeks to provide a holistic perspective of ammonia as a chemical that presents benefits and constraints for storing energy from sustainable sources. State-of-the-art knowledge provided by academics actively engaged with the topic at various fronts also enables a clear vision of the progress in each of the branches of ammonia as an energy carrier. Further, the fundamental boundaries of the use of the molecule are expanded to real technical issues for all potential technologies capable of using it for energy purposes, legal barriers that will be faced to achieve its deployment, safety and environmental considerations that impose a critical aspect for acceptance and wellbeing, and economic implications for the use of ammonia across all aspects approached for the production and implementation of this chemical as a fueling source. Herein, this work sets the principles, research, practicalities, and future views of a transition toward a future where ammonia will be a major energy player.
286 citations
TL;DR: In this article, a review of the latest progress of g-C₃N₄-based materials in visible-light-driven water splitting to hydrogen is presented.
Abstract: Graphitic carbon nitride (g-C₃N₄), a polymeric semiconductor, has become a rising star for photocatalytic energy conversion because of its facile accessibility, metal-free nature, low cost, and environmentally benign properties. This work reviews the latest progress of g-C₃N₄-based materials in visible-light-driven water splitting to hydrogen. It begins with a brief history of g-C₃N₄, followed by various engineering strategies of g-C₃N₄, such as elemental doping, copolymerization, crystalline tailoring, surface engineering, and single-atom modification, for elevated photocatalytic water decomposition. In addition, the synthesis of g-C₃N₄ in different dimensions (0D, 1D, 2D, and 3D) and configurations of a series of g-C₃N₄-based heterojunctions (type II, Z-scheme, S-scheme, g-C₃N₄/metal, and g-C₃N₄/carbon heterojunctions) were also discussed for their improvement in photocatalytic hydrogen production. Lastly, the challenges and opportunities of g-C₃N₄-based nanomaterials are provided. It is anticipated that this review will promote the further development of the emerging g-C₃N₄-based materials for more efficiency in photocatalytic water splitting to hydrogen.
139 citations
TL;DR: In this article, the adsorption-based CO2 post-combustion cap was proposed to meet the global goals established for carbon dioxide reduction. But, it is not suitable for large-scale deployment.
Abstract: Aiming at meeting the global goals established for carbon dioxide (CO2) reduction, carbon capture and storage (CCS) plays a key role. In this framework, the adsorption-based CO2 post-combustion cap...
109 citations
96 citations
TL;DR: Ionic liquids (ILs) have been extensively used in both electrolyte exploitation and electrode synthesis for supercapacitors as discussed by the authors, and three representative types (i.e., neat IL electrolytes, IL mixtures, and IL (quasi-) solid-state electrolytes) are applied to put aside the watersplitting roadblock, thus affording high charge storage under wide electrochemical stability potentials.
Abstract: Ionic liquids (ILs), composed of bulky organic cations and versatile anions, have sustainably found widespread utilizations in promising energy-storage systems. Supercapacitors, as competitive high-power devices, have drawn tremendous attention due to high-rate energy harvesting and long-term durability. The electric energy of supercapacitors is stored through the ion dynamics and physicochemical interactions at the electrolyte/electrode interface. To satisfy the high-energy request for building better supercapacitors, ILs stand out by virtue of the characteristic negligible vapor pressure and molecular designability, coupled with several fascinating features including a highly ionized environment, good thermal/chemical stability, and universal solubility/affinity. This mini-review offers an overview of recent IL utilizations in both electrolyte exploitation and electrode synthesis for supercapacitors. On the role of IL-based electrolyte components, three representative types (i.e., neat IL electrolytes, IL mixtures, and IL (quasi-)solid-state electrolytes) are applied to put aside the water-splitting roadblock, thus affording high charge storage under wide electrochemical stability potentials. On the other hand, the involvement of ILs in material science is described as microstructure-directing agents, heteroatom dopants, and carbon precursors, respectively, for the purpose of boosting the interfacial physicochemical interactions toward superior electrode capacitances. Finally, current challenges and future outlooks associated with IL media/materials are summarized for next-generation supercapacitor applications.
96 citations
TL;DR: In this paper, a review collects a wide range of initiatives and results that expose the potential of the refineries to be converted into waste refineries, and they will use their current units for the valor...
Abstract: This review collects a wide range of initiatives and results that expose the potential of the refineries to be converted into waste refineries. Thus, they will use their current units for the valor...
91 citations
TL;DR: In this paper, the salient features of the ongoing energy transition from a high to a low carbon economy are reviewed and analyzed, and it is shown that this transition will require decarbonizing th...
Abstract: In this paper, we review and analyze the salient features of the ongoing energy transition from a high to a low carbon economy. Our analysis shows that this transition will require decarbonizing th...
90 citations
TL;DR: As the typical unconventional reservoir, shale gas is believed to be the most promising alternative for the conventional resources in future energy patterns, attracting more and more attention from the energy industry as discussed by the authors.
Abstract: As the typical unconventional reservoir, shale gas is believed to be the most promising alternative for the conventional resources in future energy patterns, attracting more and more attention thro...
83 citations
TL;DR: Natural gas hydrate (NGH) is considered one of the most promising future energy sources because of its considerable reserves and high energy density, which could meet the growing global energy dema... as mentioned in this paper.
Abstract: Natural gas hydrate (NGH) is considered one of the most promising future energy sources because of its considerable reserves and high energy density, which could meet the growing global energy dema...
81 citations
TL;DR: In this article, photocatalytic CO2 reduction (PCR) into hydrocarbon fuels and chemicals such as CH4, CH3OH, HCHO, and HCOOH is a promising strategy for simultaneously solving environmental challenges and realizing...
Abstract: Photocatalytic CO2 reduction (PCR) into hydrocarbon fuels and chemicals such as CH4, CH3OH, HCHO, and HCOOH is a promising strategy for simultaneously solving environmental challenges and realizing...
80 citations
TL;DR: In this paper, the authors considered silicon (Si) to be the most promising anode material to replace graphite due to its higher theoretical capacity, and played an important role in addressing the serious problems of graphite.
Abstract: Silicon (Si) is considered to be the most promising anode material to replace graphite due to its higher theoretical capacity. Nanotechnology has played an important role in addressing the serious ...
TL;DR: To boost the use of electronic devices and driving mileage of electric vehicles, it is urgent to develop lithium-ion batteries (LIBs) with higher energy density and longer life as discussed by the authors.
Abstract: To boost the use of electronic devices and driving mileage of electric vehicles, it is urgent to develop lithium-ion batteries (LIBs) with higher energy density and longer life. High-voltage and hi...
TL;DR: In this article, N-doped porous carbonaceous CO2 sorbents were synthesized using biomass waste hazelnut shell as the raw materials, melamine as the nitridation agent, and KOH as the porogen.
Abstract: In this manuscript, N-doped porous carbonaceous CO2 sorbents were synthesized using biomass waste hazelnut shell as the raw materials, melamine as the nitridation agent, and KOH as the porogen. The...
TL;DR: This review analyzes the fundamental aspects involving the process of pyrolysis-reforming of biomass and waste plastics to find the optimum design of transition metal based reforming catalysts is the bottleneck in the development of the process and final H2 production.
Abstract: This work was carried out with the financial support from Spain's Ministries of Science, Innovation and Universities (Grant RTI2018-101678-B-I00 (MCIU/AEI/FEDER, UE) and Grant RTI2018-098283-J-I00 (MCIU/AEI/FEDER, UE)) and Science and Innovation (Grant PID2019-107357RB-I00 (AEI/FEDER, UE)) and the Basque Government (Grants IT1218-19 and KK-2020/00107). Moreover, this project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 823745.
TL;DR: A review of the application of amino acids as kinetic hydrate promoters for gas hydrate formation can be found in this paper, where the authors present perspectives on the mechanism of action for the same.
Abstract: Gas hydrates are viewed as a potential process enabler for several critical technological applications such as methane storage, hydrogen storage, gas separation, desalination, carbon dioxide capture and sequestration, etc. Hydrate based technological applications almost always require rapid hydrate formation along with high gas uptake to be economically viable. One possible approach to achieve the same is the introduction of particular additives into the system. These additives which are known as kinetic hydrate promoters (KHPs) either reduce the time required for hydrate nucleation or enhance the rate of hydrate growth or both. In recent times, amino acids, which are essential components of the human diet and thus ecofriendly materials, have emerged as a highly effective class of KHPs and unlike surfactants (traditional KHP molecules) promise a clean mode of kinetic action, i.e., no foam formation. Here we review the application of amino acids as KHPs for gas hydrate formation thus far and present perspectives on the mechanism of action for the same.
TL;DR: In this paper, a review of factors affecting the electrochemical potential of the cathode materials are reviewed and discussed, and strategies required for high-voltage phosphate polyanion cathodes are envisioned, which are expected to deliver lithium-ion battery cathodes with higher working potential and gravimetric specific capacity.
Abstract: Followed by decades of successful efforts in developing cathode materials for high specific capacity lithiumion batteries, currently the attention is on developing a high voltage battery (>5 V vs Li/Li+ ) with an aim to increase the energy density for their many fold advantages over conventional <4 V batteries. Among the various cathode materials, phosphate polyanion materials (LiMPO4, where M is a single metal or a combination of metals) showed promising candidacy given their high electrochemical potential (4.8−5 V vs Li/Li+), long cycle stability, low cost, and achieved specific capacity (∼165 mAh·g−1) near to its theoretical limit (170 mAh·g−1). In this review, factors affecting the electrochemical potential of the cathode materials are reviewed and discussed. Techniques to improve the electrical and ionic conductivities of phosphate polyanion cathodes, namely, surface coating, particle size reduction, doping, and morphology engineering, are also discussed. A processing−property correlation in phosphate polyanion materials is also undertaken to understand relative merits and drawbacks of diverse processing techniques to deliver a material with targeted functionality. Strategies required for high-voltage phosphate polyanion cathode materials are envisioned, which are expected to deliver lithium-ion battery cathodes with higher working potential and gravimetric specific capacity
TL;DR: Two-dimensional (2D) atomically thin transition metal dichalcogenide MoSe2 has been identified as one of the highly active noble-metal-free catalysts for the electrocatalytic hydrogen evolution as mentioned in this paper.
Abstract: Two-dimensional (2D) atomically thin transition metal dichalcogenide MoSe2 has been identified as one of the highly active noble-metal-free catalysts for the electrocatalytic hydrogen evolution rea...
TL;DR: The big success in marine shale gas exploration and production made China the third country worldwide to commercialize shale gas development as discussed by the authors, however, the Upper Ordovician Wufeng Formation and the...
Abstract: The big success in marine shale gas exploration and production made China the third country worldwide to commercialize shale gas development. However, the Upper Ordovician Wufeng Formation and the ...
TL;DR: The gas synthesis of nanoparticles has gained major interest by different industries and research groups for the development of new materials and their subsequent implementation in numerous devices as discussed by the authors, which can be found in the literature.
Abstract: The gas synthesis of nanoparticles has gained major interest by different industries and research groups for the development of new materials and their subsequent implementation in numerous devices...
TL;DR: The wetting characteristics of shale rocks at representative subsurface conditions remain an area of active debate as discussed by the authors, and a precise characterization of shale wettability is essential for enhanced oil and gas exploration.
Abstract: The wetting characteristics of shale rocks at representative subsurface conditions remain an area of active debate. A precise characterization of shale wettability is essential for enhanced oil and...
TL;DR: In this article, an optimized sheet size renders strong parallel sheet stacking to provide mechanical strength that withstands capillary action during aerogel formation with a high surface area (190.40 m2 g−1) and pore volume (0.261 cm3 g− 1).
Abstract: Reduce graphene oxide (rGO) aerogels with different precursor graphene oxide sheet sizes are synthesized using L-ascorbic acid reduction followed by an ambient pressure drying method. The sheet sizes determine the oxygen functionality content during aerogel formation, which subsequently affect its structural properties. The optimized sheet size renders strong parallel sheet stacking to provide mechanical strength that withstands capillary action during aerogel formation with a high surface area (190.40 m2 g−1) and pore volume (0.261 cm3 g−1). Such surface properties enhance the electrochemical properties of rGO aerogel (182 F g−1 at 0.75 A g−1) and render it to be an excellent electrode material for a supercapacitor.
TL;DR: The selective catalytic reduction (SCR) of NOx with ammonia is an effective method to remove NOx from stationary and mobile sources as discussed by the authors, and has been studied extensively as low-temper...
Abstract: The selective catalytic reduction (SCR) of NOx with ammonia is an effective method to remove NOx from stationary and mobile sources. Cerium oxides (CeOx) have been studied extensively as low-temper...
TL;DR: In this article, the main drawbacks of using biomass as pyrolysis feedstock consists of the huge variability of the different biomass resources which undermines the viability of downstream processes. In
Abstract: One of the main drawbacks of using biomass as pyrolysis feedstock consists of the huge variability of the different biomass resources which undermines the viability of downstream processes. Inheren...
TL;DR: In this paper, the restacking of metal oxides has been studied in the context of the MXene composites with various metal oxide states, showing excellent electrochemical performance due to the presence of multiple oxidation states.
Abstract: Recently, the MXene itself and its composites with various metal oxides have shown excellent electrochemical performance due to the presence of multiple oxidation states. However, the restacking of...