Adsorption Of Ethylene Research Articles

Preparation, characterization, and adsorption capacity of pyrophosphoric acid sustainable activated carbon from baijiu spent grains for risk factor mitigation

The increasing societal concern regarding the safety of alcoholic beverages necessitates the implementation of effective and safe intervention measures to enhance their safety. This study aims to repurpose the substantial spent grains generated during Baijiu production, which have a significant environmental impact, into sustainable activated carbon (as an adsorbent) by pyrophosphoric acid to alleviate these concerns directly. Precise optimization strategies were employed for simulated and authentic Baijiu samples to determine ideal conditions for carbon synthesis suitable for different alcoholic beverages (with fewer flavor compounds and rich in flavor compounds). Characterization via FT-IR and SEM confirmed the porous structure of the activated carbon. The adsorption experiments indicate that calcination temperature significantly influences adsorption efficiency, favoring selective adsorption of higher alcohols, acetaldehyde, and methanol, while simultaneously reducing acid adsorption. Compared to commercial activated carbon, spent grain carbon exhibited superior acid retention effects. Through sensory evaluation to determine application parameters, activated carbon can reduce acetaldehyde and higher alcohols in Baijiu by 9.67 % and 14.94 %, respectively, without compromising aroma. Thus, this research not only provides a novel recycling strategy for the significant waste generated in Baijiu production but also offers a green and sustainable assurance measure for the quality and safety of alcoholic beverages.

Study on adsorption and purification materials for ethylene in cold storage

In view of the lack of systematic quantitative and comparative studies on the purification effect of ethylene adsorbent in cold storage, starting from the selection of purification materials, this paper analyzed the purification effect of different zeolite materials on ethylene through a small test chamber, and screened out the best zeolite adsorbents used in self-made purification device. Combined with characterization analysis, purification efficiency evaluation and adsorption capacity of zeolite material, the removal performance of ethylene was investigated. The results showed that the zeolite samples with rough and porous surface showed better adsorption performance for ethylene. The larger the specific surface area and total pore volume, the stronger the adsorption capacity to ethylene. In addition, the presence of Na elements and mesoporous increased the exchange capacity and pore volume, which also played a certain role in the ethylene adsorption process. Experimental result demonstrates that clean air volume (CADR) of ethylene is 232 m3/h, the ethylene removal rate at 30 min is 98.19%, and the purification energy efficiency is 1.39. At the same time, the adsorption capacity of the selected zeolite sample is 1380.5 μg/g by dynamic adsorption experiment, and the service life of the filter element of the self-made purification device is estimated to be 166 days. This study can provide a theoretical basis for ethylene purification in cold storage.

Ethylene Adsorption on Alkali-Hydrophobic Zeolite Y

Zeolites HY with different hydrophobicity having Si/Al ratios of 10, 100 and 750 were modified by an ion exchange process with nitrate solutions of alkali cations in the concentration range 0.1 - 100 mM. The modified samples were characterized by ICP-OES, XRD and surface analysis with N2-adsorption. The ethylene adsorptivities of these modified zeolites were measured under degassed and non-degassed conditions. All zeolites showed the enhancement in ethylene adsorptivity upon modification, while the K+ ions modified ones showed the best enhancement. The modified hydrophobic zeolites with Si/Al ratios of 100 and 750 showed no differences in adsorptivity under the degassed and non-degassed conditions. However, for less hydrophobic zeolite (Si/Al = 10), the adsorption under the degassed condition was much higher than the adsorption under the non-degassed condition. These results indicate that the modified hydrophobic zeolites with Si/Al ratios of 100 and 750 are suitable as ethylene scavengers at ambient conditions. HIGHLIGHTS Zeolites Y with different Si/Al ratios were modified by alkali nitrate solutions The ethylene adsorptivities were measured under degassed and non-degassed conditions Zeolites showed better ethylene adsorptivity upon modification with alkali cation K+ ions modified zeolite showed the best enhancement Modified zeolites (100 and 750) suited as ethylene adsorbent at ambient conditions GRAPHICAL ABSTRACT

Selective adsorption of ethane and methane on zeolite-like imidazolate frameworks ZIF-8 and ZIF-67: effect of lattice coordination centers

Selective adsorption of ethane and methane on zeolite-like imidazolate frameworks ZIF-8 and ZIF-67: effect of lattice coordination centers

Sn-doped PdAg/Al2O3 catalysts: Efficient catalysts for the selective hydrogenation of acetylene to ethylene under industrial conditions

PdAg/Al2O3 catalysts were prepared using a simple and scalable preparation method. A systematic approach established a preparation-performance relationship which revealed that the Pd:Ag ratio and Pd reduction method affects the overall performance for the selective hydrogenation of acetylene to ethylene under industrially relevant tail-end reaction conditions. The addition of Sn improved selectivity with the optimum system achieving 97% selectivity towards ethylene, outperforming two industrial references. Density functional theory (DFT) simulations and electron microscopy analysis revealed that Sn integrates into the Pd lattice and increases the energy barrier for ethylene adsorption. This work demonstrates that Sn can be used to tailor catalyst performance for industrially relevant PdAg/Al2O3 catalysts.

Investigating the ethylene adsorption performance of scavenger films in controlled humidity conditions

Investigating the ethylene adsorption performance of scavenger films in controlled humidity conditions

Oxygen-deficient WO3 for stable visible-light photocatalytic degradation of acetaldehyde within a wide humidity range

Indoor VOCs pollution has attracted broad attention for its harm to mankind’s health recent years. Photocatalytic degradation of indoor VOCs holds great prospects in addressing these health concerns in daily life. However, traditional photocatalysts have a large recombination rate of charge carriers and a decrease of the photocatalytic degradation efficiency under high relative humidity. Herein, uniform tungsten oxide nanoparticles with enriched oxygen vacancies (WO3-U) were synthesized by a direct annealing method with urea addition, which exhibited superior performance in the visible-light photocatalysis. The reaction rate constant value of photocatalytic acetaldehyde degradation over WO3-U catalyst was above 3 times higher than that of pristine WO3 sample. More importantly, the WO3-U catalyst maintained stable and excellent photocatalytic performance at relative humidity range of 25–100 %. Except for the enhanced photogenerated charges separation, abundant oxygen vacancies could effectively accelerate O2 activation to generate •O2−, which accounted mainly for the initial conversion of acetaldehyde. Then the subsequent transformation of •O2− into •OH to promoted the final mineralization of acetaldehyde. In addition, the presence of oxygen vacancies also facilitated H2O dissociation to form surface hydroxyl groups, which increased the adsorption of acetaldehyde, resulting in the consistent photocatalytic performance of WO3-U catalyst within a wide humidity range. This work provides guidelines to design visible-light responsive photocatalysts with efficient activity at high humidity conditions for indoor VOCs degradation.

Competitive adsorption of gaseous acetic acid, ethanol and acetaldehyde onto wool powder

Natural resources are highly cost-effective adsorbents to reduce the indoor air pollution. However, there is a lack of understanding how the presence of several odor types affect their adsorption behavior. This study systematically investigates the adsorption selectivity and capacity of wool powder towards three typical odor types (acetic acid, ethanol and acetaldehyde) under single, binary and ternary systems through time-resolved spectral analysis and density functional theory (DFT) calculations. Wool powder showed different adsorption capacities for selected odor types in the single-component system. These findings were further manifested by DFT calculations to confirm the adsorption energy and surface adsorption sites between wool powder and odors. Acetic acid showed the highest competitivity among the tested odor types, followed by ethanol, which could be attributed to its high molecular weight and strong adsorption energy. This work provides new insights into adsorption mechanisms through adsorption energy analysis, promoting the application of natural proteaceous adsorbents.

Trace ethylene adsorbents Ag/F-Z5(X) for improved preservation of fruits and vegetables: Enhanced adsorption and water resistance

During the storage/transportation of fruits and vegetables, ethylene-induced over-maturation and spoilage is a serious problem. Currently developed ethylene adsorbents exhibit great potentials due to their low cost and high efficiency, but always lack of water resistance. Herein, we developed Ag/F-Z5(X) adsorbents via the modification of ZSM-5 with different amounts of NH4F followed by silver loading, which exhibits enhanced ethylene adsorption and water resistance. Among the samples, Ag/F-Z5(25) featured with the largest capacity (6.44 mg·g−1) and the best water resistance, achieving near-complete removal of trace ethylene (100 ppm) at room temperature. Based on the characterizations, NH4F modification induced a hierarchical structure within the ZSM-5 framework, concurrently enhancing surface acidity, increasing the proportion of Ag+, and improving the dispersion of metals in the adsorbents. These enhancements collectively contribute to enhanced adsorption and water resistance. Further, banana storage experiments confirmed the actual preservation ability of Ag/F-Z5(25) thanks to the better adsorption and water resistance than unmodified Ag/Z5. These findings offer meaningful insights for developing high-efficient and water-resistant adsorbents to remove trace ethylene, consequently mitigating food aste and enlarging the commercial value of agricultural products.

Ethylene control in fruit quality assurance: A material science perspective

AbstractThe waste of resources associated with fruit decay is rapidly spreading globally, threatening the interests of relevant practitioners and the health of consumer groups, and demanding precise solutions. Controlling fruit ripening through ethylene regulation is one of the most important strategies for providing high‐quality fruits. However, current materials for ethylene regulation still have difficulty realizing their application potential due to high manufacturing costs and performance deficiencies. In this review, the ethylene‐controlled release materials for ripening based on molecular encapsulation and the ethylene scavengers for preservation based on mechanisms such as oxidation, photodegradation, and adsorption are presented. We discuss and analyze a wide range of materials in terms of mechanism, performance, potential of applicability, and sustainability. The ethylene release behavior of encapsulating materials depends on the form in which the ethylene binds to the material as well as on environmental factors (humidity and temperature). For ethylene scavengers, there are a variety of scavenging mechanisms, but they generally require porous materials as adsorption carriers. We highlight the great opportunity of designing soft crystalline porous materials as efficient ethylene adsorbent due to their unique structural properties. We present this review, including a summary of practical characteristics and deficiencies of various materials, to establish a systematic understanding of fruit quality assurance materials applied to ethylene regulation, anticipating a promising prospect for these new materials.

Advanced ethylene-absorbing and cushioning depending on the 3D porous-structured fruit packaging: Toward polyurethane foam manipulation using zein and soybean oil polyol substrates

Fruits are essential sources of nutrients in our daily diet; however, their spoilage is often intensified by mechanical damage and the ethylene phytohormone, resulting in significant economic losses and exacerbating hunger issues. To address these challenges, this study presented a straightforward in situ synthesis protocol for producing Z/SOPPU foam, a 3D porous-structured fruit packaging. This innovative packaging material offered advanced ethylene-adsorbing and cushioning capabilities achieved through stirring, heating, and standing treatments. The results demonstrated that the Z/SOPPU foam, with its porous structure, served as an excellent packaging material for fruits, maintaining the intact appearance of tomatoes even after being thrown 72 times from a height of 1.5 m. Additionally, it exhibited desirable hydrophobicity (contact angle of 114.31 ± 0.82°), degradability (2.73 ± 0.88 % per 4 weeks), and efficient ethylene adsorption (adsorption rate of 13.2 ± 1.7 mg/m3/h). These remarkable characteristics could be attributed to the unique 3D micron-porous configuration, consisting of soybean oil polyol polyurethane foam for mechanical strain cushioning and zein for enhanced ethylene adsorption efficiency. Overall, this research offers an effective and original approach to the rational design and fabrication of advanced bio-based fruit packaging.

Ethylene Adsorption Study by Using Various MOFs in the CMC Film for Application in Postharvest of Fruit

Ethylene Adsorption Study by Using Various MOFs in the CMC Film for Application in Postharvest of Fruit

Improving the removal efficiency of oxygenated volatile organic compounds by defective UiO-66 regulated with water

The purification of oxygenated volatile organic compounds VOCs (OVOCs), important precursors of ozone and particulate matters, has triggered intensive research interests. UiO-66 with high photocatalytic activity have shown great potential. However, the lack of active sites severely limited the trapping and degradation of OVOCs. Herein, reo-UiO-66 with increased specific surface area, hierarchical porous structure and tunable acidic/basic sites was synthesized by simply adding water as the modulator. XRD, TGA and FTIR results confirmed the formation of reo-defects, which significantly affected the surface hydrophilicity and active sites of UiO-66. The adsorption of Lewis acidic acetaldehyde was enhanced by 265 times with coordinative unsaturated Zr acting as the dominant adsorption sites. The degradation efficiency of typical OVOCs (acetaldehyde and acetone) increased from 0% and 25% to 50% and 73%, respectively. This work provided a facile method to modulate the micro-environment in MOFs for the efficient capture and catalytic purification of OVOCs.

Zein–natamycin functional films with ethylene adsorption and fungi stasis for active food packaging applications

Zein–natamycin functional films with ethylene adsorption and fungi stasis for active food packaging applications

Selective hydrogenation of acetylene over Pd/In2O3@SiO2: The effect of the catalyst reduction temperature

Tuning the hydrogenation activity of Pd is an effective method to achieve selective hydrogenation of acetylene. The previous study shows that Pd has a strong interaction with In2O3, causing a significant change in the electronic structure of the palladium catalyst. Herein, Pd/In2O3@SiO2 was prepared by a deposition-precipitation method for selective hydrogenation of acetylene. After the reduction by flowing hydrogen, Pd-In intermetallic compounds can be formed. The concentration of the formed intermetallic compounds is closely associated with the reduction temperature. The Pd-In intermetallic compounds suppress the hydrogen activation ability of Pd and significantly weaken the adsorption of ethylene. Especially, a weak adsorption of di-σ-bonded ethylene is observed, which facilitates the desorption of ethylene and promotes the ethylene selectivity in the semi-hydrogenation of acetylene. The experimental study confirms that there exists an optimum reduction temperature (250 °C) for the formation of the Pd-In intermetallic compounds, with which ∼ 80 % ethylene selectivity and 100 % acetylene conversion have been achieved at 140 °C.

Tailoring the Electronic Metal-Support Interactions in Supported Silver Catalysts through Al modification for Efficient Ethylene Epoxidation.

Metal-modified catalysts have attracted extraordinary research attention in heterogeneous catalysis due to their enhanced geometric and electronic structures and outstanding catalytic performances. Silver (Ag) possesses necessary active sites for ethylene epoxidation, but the catalyst activity is usually sacrificed to obtain high selectivity towards ethylene oxide (EO). Herein, we report that using Al can help in tailoring the unoccupied 3d state of Ag on the MnO2 support through strong electronic metal-support interactions (EMSIs), overcoming the activity-selectivity trade-off for ethylene epoxidation and resulting in a very high ethylene conversion rate (~100 %) with 90 % selectivity for EO under mild conditions (170 °C and atmospheric pressure). Structural characterization and theoretical calculations revealed that the EMSIs obtained by the Al modification tailor the unoccupied 3d state of Ag, modulating the adsorption of ethylene (C2H4) and oxygen (O2) and facilitating EO desorption, resulting in high C2H4 conversion. Meanwhile, the increased number of positively charge Ag+ lowers the energy barrier for C2H4(ads) oxidation to produce oxametallacycle (OMC), inducing the unexpectedly high EO selectivity. Such an extraordinary electronic promotion provides new promising pathways for designing advanced metal catalysts with high activity and selectivity in selective oxidation reactions.

Tailoring the Electronic Metal‐Support Interactions in Supported Silver Catalysts through Al modification for Efficient Ethylene Epoxidation

AbstractMetal‐modified catalysts have attracted extraordinary research attention in heterogeneous catalysis due to their enhanced geometric and electronic structures and outstanding catalytic performances. Silver (Ag) possesses necessary active sites for ethylene epoxidation, but the catalyst activity is usually sacrificed to obtain high selectivity towards ethylene oxide (EO). Herein, we report that using Al can help in tailoring the unoccupied 3d state of Ag on the MnO2 support through strong electronic metal‐support interactions (EMSIs), overcoming the activity‐selectivity trade‐off for ethylene epoxidation and resulting in a very high ethylene conversion rate (~100 %) with 90 % selectivity for EO under mild conditions (170 °C and atmospheric pressure). Structural characterization and theoretical calculations revealed that the EMSIs obtained by the Al modification tailor the unoccupied 3d state of Ag, modulating the adsorption of ethylene (C2H4) and oxygen (O2) and facilitating EO desorption, resulting in high C2H4 conversion. Meanwhile, the increased number of positively charge Ag+ lowers the energy barrier for C2H4(ads) oxidation to produce oxametallacycle (OMC), inducing the unexpectedly high EO selectivity. Such an extraordinary electronic promotion provides new promising pathways for designing advanced metal catalysts with high activity and selectivity in selective oxidation reactions.

Novel ethylene scavenger based on sillimanite and bentonite clay for packaging applications: A sustainable alternative for preservation of fresh produce

Natural and chemical-free material in food packaging applications has gained interest globally with increasing demand for human health and environmental concerns. The present research aimed to develop a mineral and clay-based ethylene scavenger by mixing Sillimanite (Al2SiO5) and Bentonite (Al2H2O6Si) at different ratios to protect the deterioration of fruits and vegetables. The samples were prepared in different proportions of Sillimanite and Bentonite on a weight basis and named SL/BT (100:0), SL/BT (80:20), SL/BT (70:30), and SL/BT (50:50). The ethylene adsorption capacity of the samples was studied for 21 days under three conditions, i.e., 29±3 °C and 55 ± 3% RH, 25 °C and 75 ± 2% RH, 55 °C, and 99 ± 1% RH. The scanning electron microscopy (SEM) result determines the average particle size of sillimanite (80–100 nm) and bentonite (80–110 nm. Brunauer-Emmett-Teller (BET) result shows the surface area and pore volume of the sillimanite (8.42 m2/g and 0.039 cc/g) and bentonite (20.765 m2/g, 0.073 cc/g), higher surface area and pore volume result in higher ethylene adsorption. FTIR was performed to analyze the functional group changes after ethylene adsorption. The samples kept at 29±3 °C and 55 ± 3% RH showed the highest ethylene adsorption capacity of 84%. From the above study, the mineral clay-based material can effectively enhance the shelf life of fruits and vegetable packaging.

Construction of 3D-graphene/NH2-MIL-125 nanohybrids via amino-ionic liquid dual-mode bonding for advanced acetaldehyde photodegradation under high humidity

The development of metal organic framework (MOF)-based π-π conjugated structures capable of effectively transforming H2O from humid air to •OH radicals for VOCs photodegradation is a significant but difficult task. Herein, an amino-ionic liquid (NH2-IL) based dual-mode bridging strategy was proposed to connect 3D-graphene with NH2-MIL-125 forming IL-3DGr/NM(Ti) nanohybrids for advanced acetaldehyde photodegradation. The rational integration of these components was responsible for: (1) maintaining π-π conjugated electron transport system; (2) generating abundant coordinatively unsaturated sites and oxygen vacancies; (3) increasing surface area of the nanohybrids. With these attributes, IL-3DGr/NM(Ti) demonstrated enhanced charge separation and transportation electrochemical impedance spectroscopy (EIS): 7-times), acetaldehyde adsorption (22 %), light absorption (bandgap: 1.51 eV). The rapid H2O adsorption and photoconversion to •OH radicals by IL-3DGr/NM(Ti) enabled it to demonstrate superior CH3CHO photodegradation rate under high humidity, surpassing many state-of-the-art photocatalysts by 9 to 187 times under static air conditions and with nearly similar catalyst dosages* (photocatalyst weight and initial acetaldehyde concentration (mg ppm−1) ratio). Interestingly, the IL-3DGr/NM(Ti) photocatalytic activity was enhanced by increasing RH% up-to 80 %. Besides, the nanohybrids demonstrated tremendous stability, with only a 3.9 % decline observed after 5 consecutive-cycles. This strategy provides new prospects to improve the compatibility of graphene/MOF materials for futuristic photoelectrical applications under high humidity.

Enhanced Adsorption of Trace Ethylene on Ag/NZ5 Modified with Ammonia: Hierarchical Structure and Metal Dispersion Effects.

Trace ethylene poses a significant challenge during the storage and transportation of agricultural products, causing over-ripening, reducing shelf life, and leading to food waste. Zeolite-supported silver adsorbents show promise for efficiently removing trace ethylene. Herein, hierarchical Ag/NZ5(X) adsorbents were prepared via different ammonia modifications, which featured enhanced ethylene adsorption ability. Ag/NZ5(2.5) exhibited the largest capacity and achieved near-complete removal at room temperature with prolonged efficacy. Characterization results indicated that the ammonia modification led to the formation of a hierarchical structure in the zeolite framework, reducing diffusion resistance and increasing the accessibility of the active sites. Additionally, desilication effects increased the defectiveness, generating a stronger metal-support interaction and resulting in a higher metal dispersion rate. These findings provide valuable insights into the development of efficient adsorbents for removing trace ethylene, thereby reducing food waste and extending the shelf life of agricultural products.