Catalysis Today最新文献_第4页

Bio-based nylon intermediates from γ-valerolactone: Catalyst modifications for an enhanced selectivity to methyl 4-pentenoate 以γ-戊内酯为原料的生物基尼龙中间体：改进催化剂以提高对 4-戊烯酸甲酯的选择性

IF 5.2 2区化学 Q1 CHEMISTRY, APPLIED

Catalysis Today

Pub Date : 2024-10-10 DOI: 10.1016/j.cattod.2024.115100

Annemarie Marckwordt , Elmir Babayev , Johannes G. de Vries , Narayana V. Kalevaru , Sebastian Wohlrab

Ring-opening transesterification of bio-based γ-valerolactone (GVL) to produce a mixture of methyl pentenoate isomers (MPs) such as methyl 4-pentenoate (M4P), methyl 3-pentenoate (M3P) and methyl 2-pentenoate (M2P) has been carried out using modified Zr-containing catalysts in a gas phase continuous process. As the three MP isomers are potential nylon intermediates, this approach is sustainable from a green chemistry point of view to synthesize bio-based polymers. The reaction was carried out in a fixed bed catalytic reactor at ambient pressure and in the temperature range from 255 to 335°C. In the present study, SiO₂ supported zirconia catalysts were prepared by wet impregnation with varying Zr loadings in the range from 5 to 30 wt%. The catalysts were characterized by various techniques. The surface areas were determined by N₂ adsorption, acid-base properties by NH₃-TPD and CO₂-TPD techniques. In addition, the distinction of Lewis and Brønsted sites were also estimated by Py-FTIR. Among all catalysts, 25 % Zr/SiO₂ exhibited the best performance. The influence of various key reaction parameters on the activity/selectivity was explored and suitable reaction conditions were optimized. The conversion of GVL and product distribution was found to be strongly dependent on the reaction temperature and Zr content of the catalysts. The sum selectivity of all the three MP isomers varied in the range from 97 % to 99 %, of which M4P was always the dominant product. At low reaction temperature (255°C), M4P was the major product while M2P was a minor product. However, with increase in temperature, the selectivity of M2P and M3P increased at the expense of M4P due to isomerisation of the CC double bond. In addition, the effect of support on the best Zr loading was also explored and it was found that the SiO₂ support exhibited superior performance compared to others. In the direction of enhancing the selectivity of M4P, Cr-doping was also done onto 25Zr/SiO₂, the best catalyst of this study. Such incorporation of chromium significantly enhanced the selectivity of M4P above 80 % at acceptably high conversion of GVL.

在气相连续工艺中，使用改性含锆催化剂对生物基γ-戊内酯（GVL）进行开环酯交换反应，生成了戊烯酸甲酯异构体（MP）混合物，如 4-戊烯酸甲酯（M4P）、3-戊烯酸甲酯（M3P）和 2-戊烯酸甲酯（M2P）。由于这三种 MP 异构体是潜在的尼龙中间体，因此从绿色化学的角度来看，这种方法在合成生物基聚合物方面具有可持续性。反应在固定床催化反应器中进行，环境压力和温度范围为 255 至 335°C。在本研究中，通过湿法浸渍制备了二氧化硅支撑的氧化锆催化剂，Zr 的负载量在 5 到 30 wt% 之间。催化剂采用多种技术进行表征。通过 N2 吸附测定了表面积，通过 NH3-TPD 和 CO2-TPD 技术测定了酸碱性质。此外，还通过 Py-FTIR 对路易斯位点和布氏位点的区别进行了估计。在所有催化剂中，25% Zr/SiO2 的性能最佳。研究人员探讨了各种关键反应参数对活性/选择性的影响，并优化了合适的反应条件。研究发现，GVL 的转化率和产物分布与催化剂的反应温度和 Zr 含量密切相关。所有三种 MP 异构体的总选择性在 97 % 到 99 % 之间变化，其中 M4P 始终是主要产物。在低反应温度（255°C）下，M4P 是主要产物，而 M2P 则是次要产物。然而，随着温度的升高，由于 CC 双键的异构化，M2P 和 M3P 的选择性增加，而 M4P 的选择性降低。此外，还探讨了支持物对最佳 Zr 负载的影响，结果发现 SiO2 支持物的性能优于其他支持物。为了提高 M4P 的选择性，还在本研究的最佳催化剂 25Zr/SiO2 中掺入了铬。铬的掺入大大提高了 M4P 的选择性，在 GVL 可接受的高转化率条件下，其选择性超过 80%。

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引用次数: 0

Reaction ignition during the oxidative coupling of methane over Mn–Na2WO4/SiO2 甲烷在 Mn-Na2WO4/SiO2 氧化耦合过程中的反应点火

IF 5.2 2区化学 Q1 CHEMISTRY, APPLIED

Catalysis Today

Pub Date : 2024-10-10 DOI: 10.1016/j.cattod.2024.115097

Vitor Duarte Lage , Antônio José de Almeida , Tahyná Fontoura , Normando Jesus , José Carlos Pinto , Henrique Pacheco

The present study investigates the oxidative coupling of methane (OCM) as a viable solution for CH₄ upgrading with the benchmark Mn–Na₂WO₄/SiO₂ catalyst. The effects of space velocity on catalytic performance and ignition responses were evaluated. Experimental catalytic tests revealed a complex relationship between space velocity and C2+ product yields and a self-igniting behavior when the reaction temperature reached about 700 °C. The results indicated that the temperature difference (∆T) between the catalyst bed and the flowing gas increased with the feed flow rate and decreased with dilution of the catalyst bed (increasing with catalyst loading), which can allow the reaction ignition at lower temperatures. The present study sheds light on the interplay between reaction conditions and the ignition behavior, providing valuable insights for optimization of OCM processes and catalyst development.

本研究采用基准 Mn-Na2WO4/SiO2 催化剂研究甲烷氧化偶联（OCM）作为 CH4 升级的可行解决方案。评估了空间速度对催化性能和点火反应的影响。实验催化测试表明，空间速度与 C2+ 产物产率之间存在复杂的关系，当反应温度达到约 700 ℃ 时，会出现自燃行为。结果表明，催化剂床层与流动气体之间的温差（ΔT）随进料流速的增加而增大，随催化剂床层的稀释而减小（随催化剂装填量的增加而增大），这使得反应可以在较低温度下点燃。本研究揭示了反应条件与点火行为之间的相互作用，为优化 OCM 工艺和催化剂开发提供了宝贵的见解。

引用次数: 0

Hydrogen-free deoxygenation of oleic acid on acidic and basic ZSM-5 and Y-zeolites: Products for biofuel and reaction pathways 油酸在酸性和碱性 ZSM-5 和 Y-zeolites 上的无氢脱氧：生物燃料产品和反应途径

IF 5.2 2区化学 Q1 CHEMISTRY, APPLIED

Catalysis Today

Pub Date : 2024-10-10 DOI: 10.1016/j.cattod.2024.115094

Jose Geraldo A. Pacheco , Jose Fernando Padilha , Bianca L. Santos , Marilia R. Santos , Denisson Oliveira Liborio , Luiz A.M. Pontes , Roger Fréty , Santiago Arias

A large volume of highly acidic vegetable oils generated as waste could be utilized to produce low-cost biofuels without competing with food production. This study investigated the conversion of oleic acid (OA), used as a model fatty compound, in a micropyrolysis apparatus under conditions similar to those employed in fluidized catalytic cracking (FCC) of petroleum feedstocks. The influence of small-micropore size zeolites (ZSM-5) and large-micropore size zeolites (Y), in both their acidic H- and basic Na-forms, on the product distribution was evaluated. Oleic acid was pre-adsorbed onto the zeolites at a mass ratio Catalyst:OA = 10:1. Thermal cracking of pure oleic acid was limited, predominantly producing linear 1-alkenes and carboxylic acids. Conversion in the presence of catalysts was enhanced, resulting in the formation of a greater variety of hydrocarbons. Branched and cyclic alkanes, as well as polyaromatics hydrocarbons, were produced in greater quantities on Y zeolites compared to ZSM-5, due to the larger micropore diameter of the Y zeolite. Among the catalysts, Na-Y produced the highest number of hydrocarbons, predominantly within the gasoline range. These results are promising for the co-processing of fatty residues in the FCC, promoting the production of second-generation drop-in biofuels and bio-based chemicals, and contributing to industrial decarbonization.

作为废物产生的大量高酸性植物油可用于生产低成本生物燃料，而不会与粮食生产产生竞争。本研究调查了油酸（OA）在微热解装置中的转化情况，该装置采用了与石油原料流化催化裂化（FCC）类似的条件，将油酸作为脂肪化合物模型。评估了酸性 H 型和碱性 Na 型小微孔沸石（ZSM-5）和大微孔沸石（Y）对产物分布的影响。油酸预先吸附在沸石上，质量比为催化剂：油酸 = 10:1。纯油酸的热裂解受到限制，主要产生线性 1-烯烃和羧酸。在催化剂存在的情况下，转化率得到了提高，从而生成了更多种类的碳氢化合物。与 ZSM-5 相比，Y 型沸石上产生的支链烷烃和环状烷烃以及多芳烃的数量更多，这是因为 Y 型沸石的微孔直径更大。在各种催化剂中，Na-Y 催化剂生产的碳氢化合物数量最多，主要是汽油范围内的碳氢化合物。这些结果对于在催化裂化中协同处理脂肪残渣、促进第二代无须添加的生物燃料和生物基化学品的生产以及推动工业脱碳很有帮助。

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引用次数: 0

Bi2O2.33/Bi4O5I2-heterojunction photocatalysts for adsorption and visible light-driven degradation of pharmaceutical pollutants 用于吸附和可见光驱动降解制药污染物的 Bi2O2.33/Bi4O5I2- 异质结光催化剂

IF 5.2 2区化学 Q1 CHEMISTRY, APPLIED

Catalysis Today

Pub Date : 2024-10-10 DOI: 10.1016/j.cattod.2024.115093

Adwaa Ahmed , Abdo Hezam , Jabor Rabeah , Carsten Kreyenschulte , Norbert Steinfeldt , Sebastian Wohlrab , Jennifer Strunk

This study introduces the innovative Bi₄O₅I₂/Bi₂O_2.33 heterojunction for diclofenac (DF) degradation. Pharmaceutical pollutants, especially DF, pose significant threats to water sources, necessitating efficient treatment methods. Bi₂O_2.33, renowned for its unique ferromagnetic properties, emerges as a promising photocatalyst for pollutant degradation. Bi₄O₅I₂, known for strong visible light absorption and stability, holds potential for environmental applications. Interestingly, the inclusion of titanium dioxide (TiO₂) in the composite catalysts significantly influences their observed ferromagnetic properties, as revealed by Electron Paramagnetic Resonance (EPR) spectroscopy, by influencing the interactions within the Bi₄O₅I₂/Bi₂O_2.33 heterojunction and influencing its structure, morphology, and spin behavior. This interaction results in enhanced EPR and Ferromagnetic Resonance (FMR) signals, indicating intriguing spin interactions, polarization effects, charge transfers, surface dynamics, and stabilized magnetic domains. While the enhanced ferromagnetism holds promise for efficient charge separation and potential applications in environmental remediation, the expected boost in visible light-driven activity was not fully realized. This limitation is attributed to TiO₂ inherent inability to directly absorb visible light, hindering its utilization for enhanced photocatalysis within the heterojunction. Nevertheless, these findings elucidate the multifaceted role of TiO₂ in modulating the magnetic properties of these catalysts, offering valuable insights for future advancements in the design of advanced photocatalysts for effective environmental remediation.

本研究介绍了用于降解双氯芬酸（DF）的创新型 Bi4O5I2/Bi2O2.33 异质结。医药污染物，尤其是双氯芬酸，对水源构成了重大威胁，需要高效的处理方法。Bi2O2.33 因其独特的铁磁性能而闻名，是一种很有前景的降解污染物的光催化剂。Bi4O5I2 具有很强的可见光吸收能力和稳定性，在环境应用方面具有潜力。有趣的是，在复合催化剂中加入二氧化钛 (TiO2) 会影响 Bi4O5I2/Bi2O2.33 异质结内的相互作用，并影响其结构、形态和自旋行为，从而显著影响电子顺磁共振 (EPR) 光谱观察到的铁磁特性。这种相互作用导致 EPR 和铁磁共振 (FMR) 信号增强，表明自旋相互作用、极化效应、电荷转移、表面动力学和稳定磁畴等现象十分有趣。虽然增强的铁磁性为高效电荷分离和环境修复的潜在应用带来了希望，但预期的可见光驱动活性的提高并没有完全实现。这一局限性归因于二氧化钛本身无法直接吸收可见光，阻碍了其在异质结中用于增强光催化。尽管如此，这些发现阐明了 TiO2 在调节这些催化剂磁性能方面的多方面作用，为今后设计先进光催化剂以有效修复环境提供了宝贵的见解。

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引用次数: 0

Optimizing propylene production via acetone hydrodeoxygenation: Insights from catalytic studies with Cu/γ-Al2O3 and Hβ zeolite 通过丙酮加氢脱氧优化丙烯生产：使用 Cu/γ-Al2O3 和 Hβ 沸石进行催化研究的启示

IF 5.2 2区化学 Q1 CHEMISTRY, APPLIED

Catalysis Today

Pub Date : 2024-10-10 DOI: 10.1016/j.cattod.2024.115095

Aline C.M. Trindade , Heveline Enzweiler , Nina P.G. Salau

Propylene is a crucial light olefin in the petrochemical industry and can be produced via acetone hydrodeoxygenation, which involves two sequential reactions: first, acetone undergoes hydrogenation catalyzed by metallic sites, followed by the dehydration of the resulting isopropanol catalyzed by acidic sites. In this study, propylene production through acetone hydrodeoxygenation was investigated using a physical mixture of 35 wt% Cu/γ-Al₂O₃ and Hβ zeolite to investigate how various reaction parameters affect acetone conversion and propylene yield. Using the experimental design methodology, empirical models were developed to correlate acetone conversion (

X_{acet}

) and propylene yield

(Y_{prop})

with the ratio of 35 wt% Cu/γ-Al₂O₃ to Hβ (CR), total catalyst weight (Cw), hydrogen volumetric flow rate (FH₂) and reaction temperature (T). The maximum propylene yield achieved in the catalytic tests was 73.46 %. A long-term test demonstrated the catalyst's reusability, remaining active even after 22 hours of reaction with only a slight decrease in propylene yield. Analysis of the experimental data revealed that increasing T and Cw positively affected propylene yield, whereas higher CR and FH₂ had negative effects. According to the Pareto chart, reaction temperature was the most influential variable for propylene yield, followed by CR, FH₂ and Cw. For acetone conversion, the order of significance among the variables was T > CR > Cw > FH₂.

丙烯是石化工业中一种重要的轻质烯烃，可通过丙酮加氢脱氧反应生产，其中包括两个连续反应：首先，丙酮在金属位点的催化下发生加氢反应，然后在酸性位点的催化下使生成的异丙醇脱水。本研究使用 35 wt% Cu/γ-Al2O3 和 Hβ 沸石的物理混合物研究了丙酮加氢脱氧生成丙烯的过程，探讨了各种反应参数对丙酮转化率和丙烯产量的影响。利用实验设计方法，建立了丙酮转化率 (Xacet) 和丙烯产率 (Yprop) 与 35 wt% Cu/γ-Al2O3 与 Hβ 的比率 (CR)、催化剂总重量 (Cw)、氢气体积流量 (FH2) 和反应温度 (T) 的经验模型。催化试验中达到的最大丙烯产率为 73.46%。一项长期测试证明了催化剂的可重复使用性，即使在反应 22 小时后，催化剂仍能保持活性，丙烯产率仅略有下降。对实验数据的分析表明，T 和 Cw 的增加对丙烯产量有积极影响，而 CR 和 FH2 的增加则有消极影响。根据帕累托图表，反应温度是对丙烯产量影响最大的变量，其次是 CR、FH2 和 Cw。就丙酮转化率而言，各变量之间的显著性顺序为 T > CR > Cw > FH2。

{"title":"Optimizing propylene production via acetone hydrodeoxygenation: Insights from catalytic studies with Cu/γ-Al2O3 and Hβ zeolite","authors":"Aline C.M. Trindade , Heveline Enzweiler , Nina P.G. Salau","doi":"10.1016/j.cattod.2024.115095","DOIUrl":"10.1016/j.cattod.2024.115095","url":null,"abstract":"<div><div>Propylene is a crucial light olefin in the petrochemical industry and can be produced via acetone hydrodeoxygenation, which involves two sequential reactions: first, acetone undergoes hydrogenation catalyzed by metallic sites, followed by the dehydration of the resulting isopropanol catalyzed by acidic sites. In this study, propylene production through acetone hydrodeoxygenation was investigated using a physical mixture of 35 wt% Cu/γ-Al2O3 and Hβ zeolite to investigate how various reaction parameters affect acetone conversion and propylene yield. Using the experimental design methodology, empirical models were developed to correlate acetone conversion (<math><msub><mrow><mi>X</mi></mrow><mrow><mi>acet</mi></mrow></msub></math>) and propylene yield <math><mrow><mo>(</mo><msub><mrow><mi>Y</mi></mrow><mrow><mi>prop</mi></mrow></msub><mo>)</mo></mrow></math> with the ratio of 35 wt% Cu/γ-Al2O3 to Hβ (CR), total catalyst weight (Cw), hydrogen volumetric flow rate (FH2) and reaction temperature (T). The maximum propylene yield achieved in the catalytic tests was 73.46 %. A long-term test demonstrated the catalyst's reusability, remaining active even after 22 hours of reaction with only a slight decrease in propylene yield. Analysis of the experimental data revealed that increasing T and Cw positively affected propylene yield, whereas higher CR and FH2 had negative effects. According to the Pareto chart, reaction temperature was the most influential variable for propylene yield, followed by CR, FH2 and Cw. For acetone conversion, the order of significance among the variables was T > CR > Cw > FH2.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"445 ","pages":"Article 115095"},"PeriodicalIF":5.2,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142444986","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Unveiling the stability of mixed Zn/Co-ZIFs as catalysts for CO2 fixation into cyclic carbonates 揭示作为环碳酸盐二氧化碳固定催化剂的混合 Zn/Co-ZIF 的稳定性

IF 5.2 2区化学 Q1 CHEMISTRY, APPLIED

Catalysis Today

Pub Date : 2024-10-10 DOI: 10.1016/j.cattod.2024.115096

Francine Bertella , Christian W. Lopes , Edilson V. Benvenutti , Michèle O. de Souza

Zeolitic imidazolate frameworks (ZIFs) are a subclass of metal-organic frameworks (MOFs) which exhibit a zeolitic structure. These materials have been extensively used as catalysts in CO₂ cycloaddition with epoxides to form cyclic carbonates. However, their stability under reaction conditions is rarely investigated. In this work, four ZIFs were synthesized: monometallic ZIF-67 (with Co), ZIF-8 (with Zn), bimetallic Zn/Co-ZIF-67 (with three-dimensional structure), and Zn/Co-ZIF-L (with two-dimensional structure). Even though the solids presented different crystalline structures, textural properties, and CO₂ adsorption capacities, the bimetallic samples showed similar catalytic behavior with high yield (60–65 %) and selectivity (92–94 %) to propylene carbonate (PC). In comparison, the monometallic samples exhibited a somewhat higher yield (∼ 79 %) and selectivity (∼ 97 %) to PC. However, the characterization of the used catalysts showed a substantial loss in crystallinity and porosity for the monometallic ZIF-67 and ZIF-8. At the same time, the Zn/Co-ZIF-67 exhibited the highest stability in maintaining its original structure and porosity. Conversely, the Zn/Co-ZIF-L recrystallized into the sodalite three-dimensional structure after being used in two catalytic reactions. All used catalysts showed the same Zn local environment after the reaction, while the final Co species formed depended on the catalyst’s initial structure and chemical composition.

沸石咪唑啉框架（ZIFs）是金属有机框架（MOFs）的一个子类，具有沸石结构。这些材料已被广泛用作二氧化碳与环氧化物环化生成环状碳酸盐的催化剂。然而，很少有人研究它们在反应条件下的稳定性。本研究合成了四种 ZIF：单金属 ZIF-67（含 Co）、ZIF-8（含 Zn）、双金属 Zn/Co-ZIF-67（三维结构）和 Zn/Co-ZIF-L（二维结构）。尽管这些固体具有不同的晶体结构、纹理特性和二氧化碳吸附能力，但双金属样品表现出相似的催化行为，对碳酸丙烯酯（PC）具有较高的产率（60-65%）和选择性（92-94%）。相比之下，单金属样品对 PC 的产率（79%）和选择性（97%）略高。然而，对所使用催化剂的表征显示，单金属 ZIF-67 和 ZIF-8 的结晶度和孔隙率大幅下降。同时，Zn/Co-ZIF-67 在保持其原始结构和孔隙率方面表现出最高的稳定性。相反，Zn/Co-ZIF-L 在用于两个催化反应后重新结晶为钠长石三维结构。所有使用过的催化剂在反应后都显示出相同的 Zn 局部环境，而最终形成的 Co 种类则取决于催化剂的初始结构和化学成分。

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引用次数: 0

Metal-free carbon nitride polymeric films for the synthesis of valuable organics using a novel mesostructured photoreactor 利用新型介观结构光反应器合成有价有机物的无金属氮化碳聚合物薄膜

IF 5.2 2区化学 Q1 CHEMISTRY, APPLIED

Catalysis Today

Pub Date : 2024-10-08 DOI: 10.1016/j.cattod.2024.115090

Dânia S.M. Constantino , Joana C. Lopes , Rafael C. Carneiro , José C.B. Lopes, , Madalena M. Dias , Joaquim L. Faria , Cláudia G. Silva

Immobilised photocatalytic systems can strongly contribute to attaining more sustainable chemical processes, reducing downstream units for photocatalyst recovery and purification of the target molecules. On the other hand, it is known that this kind of photocatalytic system usually presents higher mass transfer resistance when compared with slurries and, consequently, slower kinetics. Besides, this can be even more limited for chemical synthesis using eco-friendly conditions, where combining the photocatalytic material with the best reactor design plays a fundamental role in the process efficiency. In this work, a micro-meso structured photoreactor was used to overcome these limitations, providing a large surface area per reaction volume and a higher illumination homogeneity through the entire reactor using a compact LED system. Several photocatalytic films were developed, combining different amounts of a metal-free photocatalyst (graphitic carbon nitride) with a biodegradable polymer matrix (sodium alginate). The catalytic performance was evaluated in the synthesis of aromatic aldehydes (anisaldehyde, tolualdehyde, benzaldehyde, vanillin, and piperonal from the photocatalytic oxidation of the corresponding, anisyl-, toluyl-, benzyl-, vanillyl- and piperonyl alcohols. All experimental runs were carried out under mild operation conditions, using water as solvent, room temperature and atmospheric pressure, and natural pH. The maximum performance in terms of yield was attained in the following order: anisaldehyde > tolualdehyde > piperonal > benzaldehyde > vanillin. A novel approach for photocatalytic organic synthesis with a low carbon footprint and reduced energy requirements is proposed. Moreover, the results provided in this work open a new window for the development of sustainable photocatalytic organic processes in continuous mode operation.

固定化光催化系统可以减少光催化剂回收和目标分子提纯的下游装置，从而为实现更可持续的化学工艺做出巨大贡献。另一方面，众所周知，与泥浆相比，这种光催化系统通常具有更高的传质阻力，因此动力学速度较慢。此外，这对使用生态友好型条件进行化学合成的限制更大，光催化材料与最佳反应器设计的结合对工艺效率起着至关重要的作用。在这项工作中，我们使用了一种微介质结构光反应器来克服这些限制，利用紧凑型 LED 系统为单位反应体积提供了较大的表面积，并在整个反应器中实现了更高的照明均匀性。通过将不同量的无金属光催化剂（氮化石墨碳）与可生物降解的聚合物基质（海藻酸钠）相结合，开发出了几种光催化薄膜。在合成芳香醛（茴香醛、甲苯醛、苯甲醛、香草醛和胡椒醛）的过程中，对催化性能进行了评估，这些芳香醛是由相应的茴香醇、甲苯醇、苯甲醇、香草醇和胡椒醇经光催化氧化而成。所有实验均在温和的操作条件下进行，以水为溶剂，室温、常压和自然 pH 值。最高产率依次为：茴香醛；甲苯醛；胡椒醛；苯甲醛；香兰素。该研究提出了一种低碳足迹、低能耗的光催化有机合成新方法。此外，这项工作所提供的结果为开发可持续光催化有机工艺的连续操作模式打开了一扇新窗口。

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引用次数: 0

Synergistic effects of feni bimetal-doped biochar on oxygen evolution reaction kinetics: A one-step, low-temperature pyrolysis approach 芬尼双金属掺杂生物炭对氧进化反应动力学的协同效应：一步式低温热解方法

IF 5.2 2区化学 Q1 CHEMISTRY, APPLIED

Catalysis Today

Pub Date : 2024-10-05 DOI: 10.1016/j.cattod.2024.115082

Qiaoling Liu , Baofeng Zhao , Haibin Guan , Jian Sun , Di Zhu , Bari Wulan , Laizhi Sun , Angang Song , Chongmin Wang , Qing Yao

As the hydrogen energy sector progresses, water electrolysis technology played a crucial role in producing green hydrogen. A major challenge in this endeavor lied in the oxygen evolution reaction (OER), where the overpotential has consistently been high leading to an increase in the energy demand. This study developed a one-step pyrolysis technique to transform metal-supported biomass into FeNi/NC catalysts having enhanced crystallinity and defect sites. This process without activation step using strong acids or bases reduced the operational procedures and the treatment of intermediate products, which reduced the technical difficulty. As the pyrolysis temperature increases, the metal ions in the biochar gradually formed stable metal oxides, which catalyze the alkaline OER and markedly boosted catalytic efficiency. Crucially, the abundance of lattice oxygen and oxygen vacancies in the catalyst played a key role in enhancing the OER kinetics. Notably, the catalyst pyrolyzed at 750 °C demonstrated good performance, with an overpotential of 270 mV at a concentration of 10 mA cm⁻² of the density of current, which was superior to RuO₂(η₁₀=315 mV) and IrO₂(η₁₀=300 mV). Overall, this study reported an approach for the fabrication of high-performance OER catalysts and the strategic utilization of biomass resources for application in clean energy technologies.

随着氢能源行业的发展，水电解技术在生产绿色氢气方面发挥着至关重要的作用。这项工作的一大挑战在于氧进化反应（OER），该反应的过电位一直很高，导致能源需求增加。本研究开发了一种一步热解技术，将金属支撑的生物质转化为具有更高的结晶度和缺陷位点的 FeNi/NC 催化剂。该工艺无需使用强酸或强碱进行活化，减少了操作步骤和中间产物的处理，降低了技术难度。随着热解温度的升高，生物炭中的金属离子逐渐形成稳定的金属氧化物，从而催化碱性 OER，显著提高催化效率。最重要的是，催化剂中丰富的晶格氧和氧空位在提高 OER 动力学方面发挥了关键作用。值得注意的是，在 750 °C 高温分解的催化剂表现出良好的性能，在 10 mA cm-2 的电流密度下，过电位为 270 mV，优于 RuO2（η10=315 mV）和 IrO2（η10=300 mV）。总之，本研究报告了一种制备高性能 OER 催化剂的方法，以及战略性利用生物质资源在清洁能源技术中的应用。

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引用次数: 0

Structural factors influencing photocatalytic and photoelectrochemical performance of low-dimensional ZnO nanostructures 影响低维氧化锌纳米结构光催化和光电化学性能的结构因素

IF 5.2 2区化学 Q1 CHEMISTRY, APPLIED

Catalysis Today

Pub Date : 2024-10-05 DOI: 10.1016/j.cattod.2024.115088

Hassan Ali, Ali Can Guler, Milan Masar, Jan Antos, Barbora Hanulikova, Pavel Urbanek, Muhammad Yasir, Tomas Sopik, Michal Machovsky, Ivo Kuritka

In this study, low dimensional ZnO nanostructures at three levels of complexity (primary polycrystalline, secondary nanowires, and tertiary nanodendrites) were consecutively synthesized on FTO glass substrates, and the impact of their structure and morphology on photocatalysis and photoelectrochemical (PEC) properties was explored. XRD, SEM, and Raman corroborated with PL and UV–vis measurements revealed nanocrystallite wurtzite building blocks with shape anisotropy and defect concentration increasing with the level of complexity. Four estrogenic hormones, i.e., estrone (E1), estradiol (E2), ethinylestradiol (EE2), and estriol (E3), were evaluated as model endocrine disruptors to assess the relative photodegradation of each hormone. The same trend was observed for PEC water-splitting performance of these materials as photoanodes under AM 1.5 G illumination. On the contrary, the performance on photodegradation of diclofenac as a model drug and resazurin ink discoloration test revealed superiority of the polycrystalline sample followed by the nanodendrites sample. These reductive photocatalytic pathway processes are likely to be governed by the interfacial charge transfer efficiency at the solution/catalyst boundary, while the other factors may have more intriguing roles associated with the relatively weak reduction potential of ZnO in comparison to its large oxidation potential with respect to water splitting.

本研究在 FTO 玻璃基底上连续合成了三种复杂程度的低维 ZnO 纳米结构（一级多晶、二级纳米线和三级纳米枝晶），并探讨了其结构和形态对光催化和光电化学（PEC）性能的影响。X射线衍射、扫描电镜和拉曼光谱以及聚光和紫外-可见光测量结果表明，纳米晶的钨锆石构筑块具有形状各向异性，缺陷浓度随着复杂程度的增加而增加。将四种雌激素，即雌酮（E1）、雌二醇（E2）、炔雌醇（EE2）和雌三醇（E3）作为内分泌干扰物模型进行评估，以评估每种激素的相对光降解情况。在 AM 1.5 G 光照下，这些材料作为光阳极的 PEC 分水性能也呈现出相同的趋势。相反，以双氯芬酸为模型药物的光降解性能和利马嗪油墨褪色测试表明，多晶样品的性能更优，纳米树枝状晶样品次之。这些还原性光催化途径过程可能是由溶液/催化剂边界的界面电荷转移效率决定的，而其他因素可能与氧化锌的还原电位相对较弱而氧化电位相对较大有关。

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引用次数: 0

Fabrication of mesoporous sulfated ZnO-modified g-C3N4 and TiO2 photocatalysts for CO2 reduction in gas phase 制备硫酸化 ZnO 改性 g-C3N4 和 TiO2 光催化剂用于气相二氧化碳还原

IF 5.2 2区化学 Q1 CHEMISTRY, APPLIED

Catalysis Today

Pub Date : 2024-10-05 DOI: 10.1016/j.cattod.2024.115089

L.A. Al-Hajji , Adel A. Ismail , M. Alsaidi , Ahmed Abdel Nazeer , Ahmed Mohamed El-Toni , S.F. Al-Ruwayeh , S.A. Ahmed , T. Al-Sharrah

Sulfated ZnO (S@ZnO) was synthesized using liquid self-assembly process through a sol-gel approach in the presence of F127 triblock copolymer. The obtained mesoporous ZnS was oxidized to ZnO and the rest part of ZnS formed surface sulfate species (SO₄²⁻) over the ZnO (S@ZnO) during the calcination at 450 °C. FT-IR spectrum of S@ZnO nanocomposite verified the existence of the surface ZnO sulfated, and the XPS spectrum confirmed the occurrence of S^6⁺ ions to prove the surface sulfate species (SO₄²⁻) over the sulfated ZnO. The obtained S@ZnO was incorporated with g-C₃N₄ and TiO₂ to yield S@ZnO/g-C₃N₄ and S@ZnO/TiO₂ nanocomposites. Photocatalytic CO₂ reduction at gaseous utilizing illumination and H₂O as an electron donor was conducted to produce CH₄ over the photocatalysts. The obtained S@ZnO/g-C₃N₄ and Pt/S@ZnO/g-C₃N₄ nanocomposites revealed that 3.17 and 6.36 ppm CH₄ were formed within 6 h of illumination, respectively. The CH₄ yields on the different photocatalysts were determined in the following trend of Pt/S@ZnO/g-C₃N₄ (6.36 ppm) > S@ZnO g-C₃N₄ (3.17 ppm) >g-C₃N₄, and S@ZnO (not detected). The yields of CH₄ trends were 10 % S@ZnO/TiO₂ (16.67 μmol g⁻¹ h⁻¹) > 20 % S@ZnO/TiO₂ (15.16 μmol g⁻¹ h⁻¹) > 5 % S@ZnO/TiO₂ (8.45 ppm) > S@ZnO (not detected) after 6 h of illumination. The maximum CH₄ formation rate of 10 % S@ZnO/TiO₂ nanocomposites was determined about of 16.67 μmol g⁻¹ h⁻¹. The present work is anticipated to be of great significance for highly active visible-light-induced ternary S@ZnO/TiO₂ and S@ZnO/g-C₃N₄ photocatalysts for photoreduction of CO₂.

硫酸化氧化锌（S@ZnO）是在 F127 三嵌段共聚物存在下，通过溶胶-凝胶方法，利用液态自组装工艺合成的。在 450 °C 煅烧过程中，得到的介孔 ZnS 被氧化成 ZnO，其余部分 ZnS 在 ZnO（S@ZnO）上形成表面硫酸盐（SO42-）。S@ZnO 纳米复合材料的傅立叶变换红外光谱验证了表面氧化锌硫酸盐化的存在，而 XPS 光谱则证实了 S6⁺离子的存在，从而证明硫酸盐化的氧化锌表面存在硫酸盐物种（SO42-）。得到的 S@ZnO 与 g-C3N4 和 TiO2 结合生成了 S@ZnO/g-C3N4 和 S@ZnO/TiO2 纳米复合材料。在气态利用照明和 H2O 作为电子供体的条件下，光催化 CO2 还原在光催化剂上生成 CH4。获得的 S@ZnO/g-C3N4 和 Pt/S@ZnO/g-C3N4 纳米复合材料显示，在光照 6 小时内分别生成了 3.17 和 6.36 ppm 的 CH4。在不同光催化剂上测定的 CH4 产率趋势如下：Pt/S@ZnO/g-C3N4（6.36 ppm）>S@ZnO g-C3N4（3.17 ppm）>g-C3N4，以及 S@ZnO（未检测到）。光照 6 小时后，CH4 的产率分别为 10 % S@ZnO/TiO2 (16.67 μmol g-1 h-1) > 20 % S@ZnO/TiO2 (15.16 μmol g-1 h-1) > 5 % S@ZnO/TiO2 (8.45 ppm) > S@ZnO（未检测到）。经测定，10 % S@ZnO/TiO2 纳米复合材料的最大 CH4 生成率约为 16.67 μmol g-1 h-1。预计本研究对高活性可见光诱导的 S@ZnO/TiO2 和 S@ZnO/g-C3N4 三元光催化剂光还原 CO2 具有重要意义。

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引用次数: 0