Nitrogen-Based Fuels: A Power-to-Fuel-to-Power Analysis

What are the fuels of the future? Seven representative carbon‐ and nitrogen‐based fuels are evaluated on an energy basis in a power‐to‐fuel‐to‐power analysis as possible future chemical hydrogen‐storage media. It is intriguing to consider that a nitrogen economy, where hydrogen obtained from water splitting is chemically stored on abundant nitrogen in the form of a nontoxic and safe nitrogen‐based alternative fuel, is energetically feasible.ISSN:1521-3757ISSN:0044-824

Lamellar-like Electrospun Mesoporous Ti-Al-O Nanofibers

Ceramic oxides nanofibers are promising materials as catalysts, electrodes and functional materials. In this report, a unique lamellar-like mesoporous structure was realized for the first time in a new system based on titania and alumina. The final structure was found to be highly dependent on the process conditions which are outlined herein. In view of the similar architecture we recently obtained with Fe-Al-O fibers, the pore formation mechanism we outline herein is general and is applicable to additional systems

Stickstoffbasierte Kraftstoffe: eine Power-to-Fuel-to-Power-Analyse

Wie sehen die Kraftstoffe der Zukunft aus? Das Resümee aus der hier vorgestellten Untersuchung zur Energiebilanz von sieben repräsentativen Kraftstoffen auf Basis von Kohlenstoff und Stickstoff: Es ist eine faszinierende Vorstellung, dass unser Energiesystem künftig Stickstoff aus der Atmosphäre als Speicher für nachhaltig aus Wasser produzierten Wasserstoff verwenden könnte.ISSN:1521-3757ISSN:0044-824

Electrospun Al2O3 Nanofibers Decorated wiZnO/Cu Nanosheets as Efficient Catalysts for CO2 Hydrogenation to Methanol and Dimethyl Ether

International audienceThe synthesis of methanol and dimethyl ether (DME) using green hydrogen (H2) is an attractive option to convert CO2 into chemicals of high interest. Copper-based catalysts are often used for these reactions due to their low cost compared to their noble metals-based analogs. Nevertheless, improving the performances of the Cu-based catalysts is highly desirable. In the present study, a new architecture of Cu and Cu/Zn-based catalysts supported on electrospun alumina nanofibers is presented. The catalysts were tested under various reaction conditions using the high-throughput equipment of the REALCAT platform to highlight the role of the hierarchical fibrous structure on the catalytic performances. The Cu or Cu/ZnO formed a unique structure of nanosheets, covering the surface of the alumina fibers. This exceptional morphology provides a large surface area of ~300 m2/g accessible for reaction. Maximal productivity to methanol (~1106 gmethanolkgCu-1∙h-1) and DME (760 gDMEkgCu-1∙h-1) were obtained for catalyst containing 7% wt. Cu/Zn with a Zn to Cu weight ratio of 2.3 at 300 °C and 50 bar. The promising results obtained here point out the significant advantages of using nanofiber-based catalysts for heterogeneously catalyzed reactions.La synthèse du méthanol et de l'éther diméthylique (DME) à l'aide d'hydrogène vert (H2) est une option attrayante pour convertir le CO2 en produits chimiques de grand intérêt. Les catalyseurs à base de cuivre sont souvent utilisés pour ces réactions en raison de leur faible coût par rapport à leurs analogues à base de métaux nobles. Néanmoins, l'amélioration des performances des catalyseurs à base de cuivre est hautement souhaitable. Cette étude présente une nouvelle architecture de catalyseurs à base de Cu et de Cu/Zn supportés par des nanofibres d'alumine électrofilées. Les catalyseurs ont été testés dans diverses conditions de réaction à l'aide de l'équipement à haut débit de la plateforme REALCAT afin de mettre en évidence le rôle de la structure fibreuse hiérarchique sur les performances catalytiques. Le Cu ou le Cu/ZnO ont formé une structure unique de nano-feuillets, couvrant la surface des fibres d'alumine. Cette morphologie exceptionnelle offre une grande surface de ~300 m2/g accessible à la réaction. Une productivité maximale en méthanol (~1106 g methanol.kgCu-1∙h-1) et en DME (760 g DME.kgCu-1∙h-1) a été obtenue pour le catalyseur contenant 7 % en poids de Cu/Zn avec une couche de ZnO. Cu/Zn avec un rapport pondéral Zn/Cu de 2,3 à 300 °C et 50 bar. Les résultats prometteurs obtenus ici soulignent les avantages significatifs de l'utilisation de catalyseurs à base de nanofibres pour des réactions catalysées de manière hétérogène

Electrospun Anion-Conducting Ionomer Fibers—Effect of Humidity on Final Properties

Anion-conducting ionomer-based nanofibers mats are prepared by electrospinning (ES) technique. Depending on the relative humidity (RH) during the ES process (RHES), ionomer nanofibers with different morphologies are obtained. The effect of relative humidity on the ionomer nanofibers morphology, ionic conductivity, and water uptake (WU) is studied. A branching effect in the ES fibers found to occur mostly at RHES < 30% is discussed. The anion conductivity and WU of the ionomer electrospun mats prepared at the lowest RHES are found to be higher than in those prepared at higher RHES. This effect can be ascribed to the large diameter of the ionomer fibers, which have a higher WU. Understanding the effect of RH during the ES process on ionomer-based fibers’ properties is critical for the preparation of electrospun fiber mats for specific applications, such as electrochemical devices

Performance of Cu/ZnO Nanosheets on Electrospun Al₂O₃ Nanofibers in CO₂ Catalytic Hydrogenation to Methanol and Dimethyl Ether

The synthesis of methanol and dimethyl ether (DME) from carbon dioxide (CO2) and green hydrogen (H2) offers a sustainable pathway to convert CO2 emissions into value-added products. This heterogeneous catalytic reaction often uses copper (Cu) catalysts due to their low cost compared with their noble metal analogs. Nevertheless, improving the activity and selectivity of these Cu catalysts for these products is highly desirable. In the present study, a new architecture of Cu- and Cu/Zn-based catalysts supported on electrospun alumina nanofibers were synthesized. The catalysts were tested under various reaction conditions using high-throughput equipment to highlight the role of the hierarchical fibrous structure on the reaction activity and selectivity. The Cu or Cu/ZnO formed a unique structure of nanosheets, covering the alumina fiber surface. This exceptional morphology provides a large surface area, up to ~300 m2/g, accessible for reaction. Maximal production of methanol (~1106 gmethanolKgCu−1∙h−1) and DME (760 gDMEKgCu−1∙h−1) were obtained for catalysts containing 7% wt. Cu/Zn with a weight ratio of 2.3 Zn to Cu (at 300 °C, 50 bar). The promising results in CO2 hydrogenation to methanol and DME obtained here point out the significant advantage of nanofiber-based catalysts in heterogeneous catalysis

Progress and prospective of nitrogen-based alternative fuels

Alternative fuels are essential to enable the transition to a sustainable and environmentally friendly energy supply. Synthetic fuels derived from renewable energies can act as energy storage media, thus mitigating the effects of fossil fuels on environment and health. Their economic viability, environmental impact, and compatibility with current infrastructure and technologies are fuel and power source specific. Nitrogen-based fuels pose one possible synthetic fuel pathway. In this review, we discuss the progress and current research on utilization of nitrogen-based fuels in power applications, covering the complete fuel cycle. We cover the production, distribution, and storage of nitrogen-based fuels. We assess much of the existing literature on the reactions involved in the ammonia to nitrogen atom pathway in nitrogen-based fuel combustion. Furthermore, we discuss nitrogen-based fuel applications ranging from combustion engines to gas turbines, as well as their exploitation by suggested end-uses. Thereby, we evaluate the potential opportunities and challenges of expanding the role of nitrogen-based molecules in the energy sector, outlining their use as energy carriers in relevant fields