Flexible aqueous zinc-air batteries with high energy density and safety have garnered significant attention. Gel polymer electrolytes have emerged as the preferred option over conventional liquid electrolytes due to their ability to prevent electrolyte leakage. In this study, a composite PANa-PVP-TiO2(NH2) hydrogel with high alkaline resistance and ionic conductivity is designed, where the inorganic TiO2(NH2) nanoparticles are evenly distributed and integrated into the organic dual network of polyacrylate sodium and polyvinyl pyrrolidone. The organic-inorganic hybrid structure enhances the absorption and retention capabilities for electrolyte solution, leading to impressive ionic conductivity of the gel polymer electrolyte throughout the operation of flexible aqueous zinc-air batteries. Additionally, the incorporation of TiO2(NH2) nanoparticles and the dual network construction effectively strengthen the mechanical strength and flexibility of the gel polymer electrolyte, suppressing by-products and zinc dendrite formation. The enhancements lead to the extended cycling longevity of zinc symmetric batteries and excellent power density, as well as the prolonged cycle life of flexible aqueous zinc-air batteries.
Traditional open circulating cooling water systems use a lot of water and electricity to remove waste heat. In coastal areas, closed seawater circulating cooling water systems have been used as an alternative to improve cooling efficiency. However, a comprehensive comparison of the design and advantages of the two types of cooling systems is lacking. Also, the best way to match and optimize the seawater system with the circulating water system in the closed seawater circulating cooling water system has not been fully explored. In this paper, a closed seawater cooling system under multiperiod is constructed, taking into account monthly changes in environmental factors. The mixed integer nonlinear programming model is solved by using GAMS software to evaluate and compare the economics and operability of the two cooling schemes. Meanwhile, the matching relationship of the internal subsystems of the closed seawater circulating cooling water system after coupling the air coolers is studied in depth, and the cooling load is allocated reasonably. The cases show that seawater cooling saves 9.22% of circulating water and reduces the total cost by 8.93% compared with cooling tower. The cost of the closed seawater cooling system can be reduced by 24.37% after coupling air coolers, and there is a direct corresponding matching relationship between circulating water and seawater.
While the use of fossil fuels has contributed to the progress and development of human society, the huge amount of CO2 is emitted, which has led to the deterioration of the ecological environment. Converting CO2 into valuable methanol is a key strategy for its utilization. In2O3 catalyst has attracted much attention due to its high selectivity and performance in methanol production. This paper reviews the structural characteristics, catalytic sites and pathways of In2O3, and the latest research progress of In2O3-based catalysts in CO2 hydrogenation to methanol. Moreover, the review outlines various strategies to enhance In-based catalysts, including: (I) loading metal particles to promote H2 dissociation, (II) formation of metal-In2O3 interfaces to enhance CO2 adsorption, (III) bimetallic catalysts to improve catalytic kinetics, (IV) combining In2O3 with metal oxides to stabilize surface oxygen vacancies, (V) constructing solid-solution catalysts, and (VI) combining with other catalysts to construct composite catalysts, etc. In2O3-based catalysts have broad application prospects in the field of CO2 hydrogenation to methanol. Through various structural and principle innovations, it is expected to improve the comprehensive performance and provide theoretical guidance for catalyst design.
The steam reforming of bio-oil can provide a sustainable means to produce hydrogen, while tar steam reforming can significantly enhance the efficiency of the biomass gasification process. Bio-oils and tars are highly complex mixtures, and while there has been extensive research on the reforming of small oxygenates and aliphatic hydrocarbons, there have been comparatively much less studies on aromatics reforming. In the current work, we present a comparative study of the steam reforming of hydroquinone, benzyl alcohol and toluene, selected as model compounds of the aromatic fraction of bio-oils and tars with different functional groups. The effect of temperature, partial pressure of reactants, and contact time is studied over a Rh catalyst supported on γ-Al2O3. Across the range of conditions studied, hydroquinone is found to be more reactive, followed by benzyl alcohol, and, lastly, toluene. The differences are attributed to the presence of hydroxyl groups in the case of the former two compounds, versus a methyl group in the case of toluene, effectively correlating activity with the O/C ratio in the compounds’ molecule. Nonetheless, similar pathways are observed, with methane, benzene, naphthalene and toluene (during hydroquinone and benzyl alcohol reforming) detected as products in addition to carbon oxides and hydrogen.
Polylactic acid, a biodegradable polymer derived from renewable resources, is increasingly used in food packaging due to its transparency, renewability, and food safety. However, its mechanical properties, heat resistance, and barrier performance present significant challenges that limit its application. Currently, there is a lack of comprehensive literature addressing methods to optimize polylactic acid’s performance for various food packaging application. Hence, this review provides an overview of polylactic acid production processes, including the synthesis of lactic acid and lactide, as well as methods such as polycondensation and ring-opening polymerization. We critically examine the advantages and limitations of polylactic acid in various food packaging contexts, focusing on strategies to enhance its mechanical properties, barrier performance against oxygen and water vapor, surface hydrophobicity, thermal stability, and resistance to ultraviolet light. Furthermore, we summarize recent advancements in polylactic acid applications for food packaging, highlighting innovations in antioxidant, antimicrobial, and freshness indicator packaging. These developments underscore the significant potential of polylactic acid in the food packaging sector and offer valuable insights for future research directions.
Single-atom catalysts are highly effective in catalyzing a wide range of reactions owing to their capacity to have precise coordination patterns and fully leverage the potential of metal atoms. Although several techniques have been reported for the preparation of single-atom catalysts, adopting a convenient method to construct them still has a challenge. In this work, we report a convenient method for the preparation of Zr-based single-atom catalyst that takes advantage of the nanoconfined environments between the template and silica wall in template-occupied silica SBA-15. After introducing Zr-containing precursor into the nanoconfined environments of the template-occupied silica SBA-15 using solid-phase milling, Zr-based single-atom catalysts were produced via the following calcination step. Density functional theory calculations and experimental findings show that Zr atoms form Zr–O–Si structure in the silica walls. The Zr single-atom catalyst synthesized using the nanoconfined environments exhibited notably superior catalytic performance in the synthesis of benzyl acetate from the esterification reaction between acetic acid and benzyl alcohol (63.3% yield), outperforming the counterpart that synthesized without such nanoconfined environments (19.8% yield).
Exploiting advanced transition metal based electrocatalysts is critical for the oxygen evolution reaction (OER) due to their high efficiency in an alkaline environment for water splitting. Herein, CoS2 nanosheets were synthesized through simple hydrothermal process and sulfurized layered β-Co(OH)2 nanosheets as a precursor. The regulation strategy of hexamethylenetetramine was employed to create layered single-crystal β-Co(OH)2 nanosheets. X-ray absorption fine structure indicates the crystal phase reconstructions occur on β-Co(OH)2 surface during the sulfidation reaction. The sulfurized β-Co(OH)2 nanosheets present an overpotential of only 297 mV to reach 10 mA·cm–2, a low Tafel slope of 71.7 mV·dec–1 and excellent stability for OER. The results clarified that the CoS2 nanosheets excellent OER performance is attributable to cobalt sulfide sheet structure and structural changes by sulfur dopants. The results of the sulfurized layered β-Co(OH)2 to produce CoS2 nanosheets indicate that this strategy may represents a potential replacement for oxygen evolution application, particularly for the large-scale production of water splitting catalysts.
