Sandra Yazmin Arzate Salgado, Ana Yañez-Aulestia, Rosa-María Ramírez-Zamora
Following the goals of the circular economy, this work demonstrates that an industrial by-product can be used in environmental remediation. Metallurgical slag and citric acid were used to form an Fe:Cit complex by simultaneously carrying out the lixiviation of the iron and the chelating stages with an 87% iron recovery. This complex was evaluated in the photo-Fenton process to produce HO• through salicylic acid dosimetry or salicylic acid hydroxylation, producing 0.13 ± 0.1 mM HO• after 30 min of operation; such a value is three orders of magnitude higher than the one reported for the metallurgical slag (as a heterogeneous catalyst, 22 μM) in the photo-Fenton-like process. The system was tested for its ability to degrade a mixture of drugs, including dexamethasone (DEX), naproxen (NAP), and ketorolac (KTR), which are often used to treat the symptoms of COVID-19. The drug degradation tests were performed in two stages. In the first stage, the Fe:Cit complex from the metallurgical slag was compared to the one formed by analytical-grade reactants; the drug degradation was faster for the former, with the major difference being observed at 5 cm and 500 W/m2. Here, 85–90% of the drugs was degraded in 5 min using Fe:Cit from slag, while at least 20 min was necessary to achieve such degradation with the analytical reagent, conceivably because of the trace compounds being lixiviated from the slag. Then, the effects of the liquid depth (5, 10, and 15 cm) and irradiance (250, 500, and 750 W/m2) were tested; the pseudo-first-order kinetic degradation constants for the three model pollutants were in the range of 0.009 > kD > 0.09 min−1, showing that degradation is more feasible for DEX than for NAP and KRT because the radical attack feasibility is related to the molecular structures.
{"title":"The Direct Formation of an Iron Citrate Complex Using a Metallurgical Slag as an Iron Source for Micropollutant Removal via the Photo-Fenton Process","authors":"Sandra Yazmin Arzate Salgado, Ana Yañez-Aulestia, Rosa-María Ramírez-Zamora","doi":"10.3390/catal14070426","DOIUrl":"https://doi.org/10.3390/catal14070426","url":null,"abstract":"Following the goals of the circular economy, this work demonstrates that an industrial by-product can be used in environmental remediation. Metallurgical slag and citric acid were used to form an Fe:Cit complex by simultaneously carrying out the lixiviation of the iron and the chelating stages with an 87% iron recovery. This complex was evaluated in the photo-Fenton process to produce HO• through salicylic acid dosimetry or salicylic acid hydroxylation, producing 0.13 ± 0.1 mM HO• after 30 min of operation; such a value is three orders of magnitude higher than the one reported for the metallurgical slag (as a heterogeneous catalyst, 22 μM) in the photo-Fenton-like process. The system was tested for its ability to degrade a mixture of drugs, including dexamethasone (DEX), naproxen (NAP), and ketorolac (KTR), which are often used to treat the symptoms of COVID-19. The drug degradation tests were performed in two stages. In the first stage, the Fe:Cit complex from the metallurgical slag was compared to the one formed by analytical-grade reactants; the drug degradation was faster for the former, with the major difference being observed at 5 cm and 500 W/m2. Here, 85–90% of the drugs was degraded in 5 min using Fe:Cit from slag, while at least 20 min was necessary to achieve such degradation with the analytical reagent, conceivably because of the trace compounds being lixiviated from the slag. Then, the effects of the liquid depth (5, 10, and 15 cm) and irradiance (250, 500, and 750 W/m2) were tested; the pseudo-first-order kinetic degradation constants for the three model pollutants were in the range of 0.009 > kD > 0.09 min−1, showing that degradation is more feasible for DEX than for NAP and KRT because the radical attack feasibility is related to the molecular structures.","PeriodicalId":505577,"journal":{"name":"Catalysts","volume":" 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141677369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
B. Khussain, Alexandr Sass, Alexandr Brodskiy, Kenzhegul Rakhmetova, Ivan Torlopov, Magira Zhylkybek, T. Baizhumanova, S. Tungatarova, A. Khussain, Murat Zhurinov, A.ZH. Kenessary, Ranida Tyulebayeva, Alexandr Logvinenko, Yernar Narimanov
In order to establish the formation patterns of the Co–Mg oxide system, samples with different Co:Mg ratios and heat treatment temperatures were synthesized and studied. A study of the samples confirmed the phase transition of MgxCo2–xO4 spinels into the corresponding solid solutions at 800–900 °C. The similarity of the formation patterns for different compositions is shown. The rocksalt oxide in low-temperature samples is an anion-modified paracrystalline phase that forms a “true” solid solution only upon spinel decomposition. The TPR profiles of the decomposed Co3O4 spinel show surface Co3O4 peaks and a wide peak corresponding to the well-crystallized CoO, while partial Co3O4 TPR up to 380 °C results in dispersed and amorphous CoO. The high-temperature non-stoichiometric samples are poorly reduced, indicating their low oxygen reactivity. Spinel reoxidation after heat treatment to 1100 °C by calcination at 750 °C showed complete regeneration for MgCo2O4–Co3O4 samples and its absence in case of an excess of MgO relative to stoichiometry.
{"title":"Patterns of Formation of Binary Cobalt–Magnesium Oxide Combustion Catalysts of Various Composition","authors":"B. Khussain, Alexandr Sass, Alexandr Brodskiy, Kenzhegul Rakhmetova, Ivan Torlopov, Magira Zhylkybek, T. Baizhumanova, S. Tungatarova, A. Khussain, Murat Zhurinov, A.ZH. Kenessary, Ranida Tyulebayeva, Alexandr Logvinenko, Yernar Narimanov","doi":"10.3390/catal14070425","DOIUrl":"https://doi.org/10.3390/catal14070425","url":null,"abstract":"In order to establish the formation patterns of the Co–Mg oxide system, samples with different Co:Mg ratios and heat treatment temperatures were synthesized and studied. A study of the samples confirmed the phase transition of MgxCo2–xO4 spinels into the corresponding solid solutions at 800–900 °C. The similarity of the formation patterns for different compositions is shown. The rocksalt oxide in low-temperature samples is an anion-modified paracrystalline phase that forms a “true” solid solution only upon spinel decomposition. The TPR profiles of the decomposed Co3O4 spinel show surface Co3O4 peaks and a wide peak corresponding to the well-crystallized CoO, while partial Co3O4 TPR up to 380 °C results in dispersed and amorphous CoO. The high-temperature non-stoichiometric samples are poorly reduced, indicating their low oxygen reactivity. Spinel reoxidation after heat treatment to 1100 °C by calcination at 750 °C showed complete regeneration for MgCo2O4–Co3O4 samples and its absence in case of an excess of MgO relative to stoichiometry.","PeriodicalId":505577,"journal":{"name":"Catalysts","volume":"42 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141683069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mingyue Liu, Gang Chen, Zhenjun Song, Zhicai He, Aiguo Zhong, Mei Cui
Catalytic dechlorination of organic chlorides by palladium (Pd) with HCOOH represents one of the most effective and promising techniques for environmental remediation. In this study, we adopted alkaline-modified porous natural sponge as support of a Pd nanocatalyst (Pd@M-Sponge) and HCOOH as a hydrogen source for the hydrodechlorination of florfenicol (FF), o-chlorophenol (o-CP), and p-chlorophenol (p-CP). Favorable conversion efficiency of FF, o-CP, and p-CP was achieved at 25 °C and atmospheric pressure attributed to the small diameter and high catalytic reactivity of the prepared Pd NPs, in addition to the slight internal mass transfer limitation of the prepared Pd@M-Sponge. High reaction rate constants were obtained even in the conditions of a low molar ratio of HCOOH to p-CP (10:1) and a high concentration of p-CP (500 mg/L). The prepared catalyst also demonstrated superior recyclability without any obvious decrease in catalytic reactivity in 20 successive p-CP dechlorination cycles. This work provides an ideal recyclable and cost-effective catalyst based on renewable and biocompatible natural material for the catalytic hydrodechlorination of chlorinated organic pollutants with formic acid and a new view for the exploration and designing of highly reactive and stable catalysts for hydrodechlorination.
{"title":"Catalytic Dechlorination of Three Organochlorides by Recyclable Nano-Palladium-Engineered Natural Sponge with Formic Acid","authors":"Mingyue Liu, Gang Chen, Zhenjun Song, Zhicai He, Aiguo Zhong, Mei Cui","doi":"10.3390/catal14070424","DOIUrl":"https://doi.org/10.3390/catal14070424","url":null,"abstract":"Catalytic dechlorination of organic chlorides by palladium (Pd) with HCOOH represents one of the most effective and promising techniques for environmental remediation. In this study, we adopted alkaline-modified porous natural sponge as support of a Pd nanocatalyst (Pd@M-Sponge) and HCOOH as a hydrogen source for the hydrodechlorination of florfenicol (FF), o-chlorophenol (o-CP), and p-chlorophenol (p-CP). Favorable conversion efficiency of FF, o-CP, and p-CP was achieved at 25 °C and atmospheric pressure attributed to the small diameter and high catalytic reactivity of the prepared Pd NPs, in addition to the slight internal mass transfer limitation of the prepared Pd@M-Sponge. High reaction rate constants were obtained even in the conditions of a low molar ratio of HCOOH to p-CP (10:1) and a high concentration of p-CP (500 mg/L). The prepared catalyst also demonstrated superior recyclability without any obvious decrease in catalytic reactivity in 20 successive p-CP dechlorination cycles. This work provides an ideal recyclable and cost-effective catalyst based on renewable and biocompatible natural material for the catalytic hydrodechlorination of chlorinated organic pollutants with formic acid and a new view for the exploration and designing of highly reactive and stable catalysts for hydrodechlorination.","PeriodicalId":505577,"journal":{"name":"Catalysts","volume":"3 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141681273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The perpetually fluctuating economic and environmental climate significantly increases the demand for alternative fuel sources. The utilization of hydrogen gas is a viable option for such a fuel source. Hydrogen is one of the most energy-dense known substances; however, it is unfortunately also highly volatile, especially in the diatomic gaseous state most commonly used to store it. The utilization of a hydrogen feedstock material such as sodium borohydride (NaBH4) may prove to mitigate this danger. When NaBH4 reacts with water, hydrogen stored within its chemical structure is released. However, the rate of hydrogen release is slow and thus necessitates a catalyst. Platinum nanoparticles were chosen to act as a catalyst for the reaction, and to prevent them from conglomerating, they were embedded in a backbone of mesoporous carbon material (MCM) derived from a sustainable corn starch source. The nanocomposite (Pt-MCM) was characterized via transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). Pt-MCM underwent catalytic testing, revealing that the catalytic activity of the Pt-MCM composite catalysts increased with increasing quantities of sodium borohydride, lower pH levels, and higher temperatures. The activation energy of the catalyzed reaction was found to be 37.7 kJ mol−1. Reusability experiments showed an initial drop off in hydrogen production after the first trial but subsequent stability. This Pt-MCM catalyst’s competitive activation energy and sustainable MCM backbone derived from readily available corn starch make it a promising option for optimizing the hydrogen generation reaction of NaBH4.
持续波动的经济和环境气候大大增加了对替代燃料来源的需求。氢气的利用是这种燃料来源的一个可行选择。氢气是已知能量密度最高的物质之一，但不幸的是，它也极易挥发，尤其是在最常用于储存氢气的二原子气态下。利用硼氢化钠（NaBH4）等氢原料材料可能会减轻这种危险。当 NaBH4 与水反应时，其化学结构中储存的氢就会释放出来。然而，氢的释放速度很慢，因此需要催化剂。我们选择了铂纳米粒子作为反应的催化剂，并将其嵌入从可持续玉米淀粉中提取的介孔碳材料（MCM）的骨架中，以防止它们凝结成团。通过透射电子显微镜（TEM）、扫描电子显微镜（SEM）、能量色散 X 射线光谱（EDS）和 X 射线衍射（XRD）对纳米复合材料（Pt-MCM）进行了表征。对 Pt-MCM 进行的催化测试表明，Pt-MCM 复合催化剂的催化活性随着硼氢化钠用量的增加、pH 值的降低和温度的升高而提高。催化反应的活化能为 37.7 kJ mol-1。可重复使用性实验表明，在第一次试验后，氢气产量会出现初步下降，但随后会保持稳定。这种 Pt-MCM 催化剂的活化能很有竞争力，而且其 MCM 骨架可持续地从容易获得的玉米淀粉中提取，这使其成为优化 NaBH4 制氢反应的一个很有前景的选择。
{"title":"Application of Platinum Nanoparticles Decorating Mesoporous Carbon Derived from Sustainable Source for Hydrogen Evolution Reaction","authors":"Erik Biehler, Qui Quach, Tarek M. Abdel-Fattah","doi":"10.3390/catal14070423","DOIUrl":"https://doi.org/10.3390/catal14070423","url":null,"abstract":"The perpetually fluctuating economic and environmental climate significantly increases the demand for alternative fuel sources. The utilization of hydrogen gas is a viable option for such a fuel source. Hydrogen is one of the most energy-dense known substances; however, it is unfortunately also highly volatile, especially in the diatomic gaseous state most commonly used to store it. The utilization of a hydrogen feedstock material such as sodium borohydride (NaBH4) may prove to mitigate this danger. When NaBH4 reacts with water, hydrogen stored within its chemical structure is released. However, the rate of hydrogen release is slow and thus necessitates a catalyst. Platinum nanoparticles were chosen to act as a catalyst for the reaction, and to prevent them from conglomerating, they were embedded in a backbone of mesoporous carbon material (MCM) derived from a sustainable corn starch source. The nanocomposite (Pt-MCM) was characterized via transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). Pt-MCM underwent catalytic testing, revealing that the catalytic activity of the Pt-MCM composite catalysts increased with increasing quantities of sodium borohydride, lower pH levels, and higher temperatures. The activation energy of the catalyzed reaction was found to be 37.7 kJ mol−1. Reusability experiments showed an initial drop off in hydrogen production after the first trial but subsequent stability. This Pt-MCM catalyst’s competitive activation energy and sustainable MCM backbone derived from readily available corn starch make it a promising option for optimizing the hydrogen generation reaction of NaBH4.","PeriodicalId":505577,"journal":{"name":"Catalysts","volume":"28 47","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141684661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Heterogeneous Fenton technology was employed for the advanced treatment of Maotai-flavored Baijiu wastewater. Novel catalysts were prepared by loading different active ingredients (Mn, Fe, and Cu) on γ-Al2O3 using an impregnation method. The effects of active ingredient, reaction time, initial pH, H2O2 dosage, catalyst dosage, and other factors on the reaction were examined. The properties of the new catalysts were analyzed using BET analysis, XPS, and SEM. Moreover, the mechanisms of Fenton-like oxidation and its reaction kinetics were explored through experiments and analyses including GC–MS and intermediate active species scavenging by tertiary butyl alcohol (TBA) and/or para-benzoquinone. The results revealed that the most effective removal of organic matter was achieved with a Mn-Fe/Al (2:1 wt%) catalyst dosage of 30 g/100 g water, pH of 5.0, H2O2 dosage of 0.3 g/L, and reaction time of 60 min; the effluent COD value was 12 ± 1 mg/L, and the degradation rate was 65.7 ± 3%, approximately 14% higher than that of the conventional Fenton catalyst under similar conditions; moreover, the catalytic efficacy remained high after seven cycles. Kinetic analysis indicated that the heterogeneous Fenton oxidation reaction followed a third-order kinetics model, with R2 = 0.9923 and K = 0.0006 min−1.
{"title":"Development of a γ-Al2O3-Based Heterogeneous Fenton-like Catalyst and Its Application in the Advanced Treatment of Maotai-Flavored Baijiu Wastewater","authors":"Benfu Luo, Yujing Yan, Jinyin Li, Fei Guo, Weiwei Huang, Xi Yang, Haiyan Ning, Qicheng Kang, Haixing He, Xuanyu Zhou, Xiang Zhou, Shijie Wang, Yuhang Liu","doi":"10.3390/catal14070422","DOIUrl":"https://doi.org/10.3390/catal14070422","url":null,"abstract":"Heterogeneous Fenton technology was employed for the advanced treatment of Maotai-flavored Baijiu wastewater. Novel catalysts were prepared by loading different active ingredients (Mn, Fe, and Cu) on γ-Al2O3 using an impregnation method. The effects of active ingredient, reaction time, initial pH, H2O2 dosage, catalyst dosage, and other factors on the reaction were examined. The properties of the new catalysts were analyzed using BET analysis, XPS, and SEM. Moreover, the mechanisms of Fenton-like oxidation and its reaction kinetics were explored through experiments and analyses including GC–MS and intermediate active species scavenging by tertiary butyl alcohol (TBA) and/or para-benzoquinone. The results revealed that the most effective removal of organic matter was achieved with a Mn-Fe/Al (2:1 wt%) catalyst dosage of 30 g/100 g water, pH of 5.0, H2O2 dosage of 0.3 g/L, and reaction time of 60 min; the effluent COD value was 12 ± 1 mg/L, and the degradation rate was 65.7 ± 3%, approximately 14% higher than that of the conventional Fenton catalyst under similar conditions; moreover, the catalytic efficacy remained high after seven cycles. Kinetic analysis indicated that the heterogeneous Fenton oxidation reaction followed a third-order kinetics model, with R2 = 0.9923 and K = 0.0006 min−1.","PeriodicalId":505577,"journal":{"name":"Catalysts","volume":"44 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141709739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rocio Solis-Palacios, Graciela Espinosa-Luna, C. Peña-Montes, R. Quintana-Castro, M. Sánchez-Otero, R. Oliart-Ros
Hydrolases are the most popular enzymes, and among the most valuable in biotechnological applications. Some hydrolases, such as lipases, esterases, proteases, cellulases and amylases, are used in the food industry and the production of biopharmaceuticals, biofuels, biopolymers and detergents. Of special interest are those obtained from thermophilic microorganisms. Although there is great microbial diversity in extreme environments, the investigations aimed at detecting and isolating enzymes with potential for polyester degradation such as polyethylene terephthalate (PET) are limited. In this work, we explored the metagenomic library of an oil-enriched soil sample from the “Los Humeros” geothermal field by means of in silico probes in search for enzymes potentially able to degrade polyesters. Using conserved motifs and activity-relevant sites of reported polyester hydrolases, we designed probes that allowed us to identify 6 potential polyester hydrolases in the metagenome. Three-dimensional structure prediction revealed a canonical α/β fold and a cap covering the active site of the enzymes. The catalytic triads were composed of Ser, His and Asp. Structural comparison, substrate binding site analysis and molecular docking suggested their potential as polyester hydrolases, particularly cutinases and PETases. An enzyme, REC98271, was cloned, expressed and characterized, showing thermophilic properties and preference for short-chain substrates. These findings contribute to our understanding of enzyme diversity in “Los Humeros” metagenome and their potential applications in biodegradation and recycling processes.
水解酶是最受欢迎的酶，也是生物技术应用中最有价值的酶之一。一些水解酶，如脂肪酶、酯酶、蛋白酶、纤维素酶和淀粉酶，可用于食品工业和生物制药、生物燃料、生物聚合物和洗涤剂的生产。从嗜热微生物中获得的酶尤其令人感兴趣。虽然极端环境中的微生物种类繁多，但旨在检测和分离具有降解聚酯（如聚对苯二甲酸乙二酯）潜力的酶的研究却很有限。在这项工作中，我们通过硅探针探索了 "Los Humeros "地热田富含石油的土壤样本的元基因组库，以寻找可能降解聚酯的酶。利用已报道的聚酯水解酶的保守基团和活性相关位点，我们设计了探针，从而在元基因组中发现了 6 种潜在的聚酯水解酶。三维结构预测显示，这些酶的活性位点有一个典型的α/β折叠和一个覆盖物。催化三元组由 Ser、His 和 Asp 组成。结构比较、底物结合位点分析和分子对接表明，它们具有作为聚酯水解酶，特别是角叉菜胶酶和 PET 酶的潜力。克隆、表达和鉴定了一种名为 REC98271 的酶，该酶具有嗜热特性并偏好短链底物。这些发现有助于我们了解 "Los Humeros "元基因组中酶的多样性及其在生物降解和回收过程中的潜在应用。
{"title":"Selection of Putative Polyester Hydrolases from the Metagenome of Los Humeros Geothermal Field by Means of In Silico Probes","authors":"Rocio Solis-Palacios, Graciela Espinosa-Luna, C. Peña-Montes, R. Quintana-Castro, M. Sánchez-Otero, R. Oliart-Ros","doi":"10.3390/catal14060379","DOIUrl":"https://doi.org/10.3390/catal14060379","url":null,"abstract":"Hydrolases are the most popular enzymes, and among the most valuable in biotechnological applications. Some hydrolases, such as lipases, esterases, proteases, cellulases and amylases, are used in the food industry and the production of biopharmaceuticals, biofuels, biopolymers and detergents. Of special interest are those obtained from thermophilic microorganisms. Although there is great microbial diversity in extreme environments, the investigations aimed at detecting and isolating enzymes with potential for polyester degradation such as polyethylene terephthalate (PET) are limited. In this work, we explored the metagenomic library of an oil-enriched soil sample from the “Los Humeros” geothermal field by means of in silico probes in search for enzymes potentially able to degrade polyesters. Using conserved motifs and activity-relevant sites of reported polyester hydrolases, we designed probes that allowed us to identify 6 potential polyester hydrolases in the metagenome. Three-dimensional structure prediction revealed a canonical α/β fold and a cap covering the active site of the enzymes. The catalytic triads were composed of Ser, His and Asp. Structural comparison, substrate binding site analysis and molecular docking suggested their potential as polyester hydrolases, particularly cutinases and PETases. An enzyme, REC98271, was cloned, expressed and characterized, showing thermophilic properties and preference for short-chain substrates. These findings contribute to our understanding of enzyme diversity in “Los Humeros” metagenome and their potential applications in biodegradation and recycling processes.","PeriodicalId":505577,"journal":{"name":"Catalysts","volume":"13 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141343446","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The O2 dissociative adsorption serves as a pivotal criterion for assessing the efficacy of oxygen reduction catalysts. We conducted a systematic investigation into O2 dissociative adsorption on the Pt-skin Pt3Cu(111) surface by means of the density functional theory (DFT). The computational findings reveal that the O2 adsorption on Pt-skin Pt3Cu(111) surface exhibits comparatively lower stability when contrasted with that on the Pt(111) surface. For O2 dissociation, two paths have been identified. One progresses from the t-f-b state towards the generation of two oxygen atoms situated within nearest-neighbour hcp sites. The other commences from the t-b-t state, leading to the generation of two oxygen atoms occupying nearest-neighbour fcc sites. Moreover, the analysis of the energy barrier associated with O2 dissociation indicates that O2 on the Pt-skin Pt3Cu(111) surface is more difficult to dissociate than on the Pt(111) surface. This study can offer a valuable guide for the practical application of high-performance oxygen reduction catalysts.
{"title":"First Principles Study of O2 Dissociative Adsorption on Pt-Skin Pt3Cu(111) Surface","authors":"Yanlin Yu, Huaizhang Gu, Mingan Fu, Ying Wang, Xin Fan, Mingqu Zhang, Guojiang Wu","doi":"10.3390/catal14060382","DOIUrl":"https://doi.org/10.3390/catal14060382","url":null,"abstract":"The O2 dissociative adsorption serves as a pivotal criterion for assessing the efficacy of oxygen reduction catalysts. We conducted a systematic investigation into O2 dissociative adsorption on the Pt-skin Pt3Cu(111) surface by means of the density functional theory (DFT). The computational findings reveal that the O2 adsorption on Pt-skin Pt3Cu(111) surface exhibits comparatively lower stability when contrasted with that on the Pt(111) surface. For O2 dissociation, two paths have been identified. One progresses from the t-f-b state towards the generation of two oxygen atoms situated within nearest-neighbour hcp sites. The other commences from the t-b-t state, leading to the generation of two oxygen atoms occupying nearest-neighbour fcc sites. Moreover, the analysis of the energy barrier associated with O2 dissociation indicates that O2 on the Pt-skin Pt3Cu(111) surface is more difficult to dissociate than on the Pt(111) surface. This study can offer a valuable guide for the practical application of high-performance oxygen reduction catalysts.","PeriodicalId":505577,"journal":{"name":"Catalysts","volume":"49 21","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141339252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yajie Wang, Cui Qiu, Peng Cheng, Yuqing Li, Yunlong Ma, Xiuzhen Tao, Bo Weng, Gilles Mailhot
In this study, Fe/Mn/Mg2-LDH was utilized for the first time as a catalyst for peroxymonosulfate (PMS) activation to facilitate the removal of Orange II. This composite was characterized using various techniques, such as XRD, FTIR, SEM-EDS, BET, and XPS. The results revealed a well-defined lamellar structure of Fe/Mn/Mg2-LDH with a metal molar ratio of Fe/Mn/Mg at 1:1:2. Moreover, the structural stability of Fe/Mn/Mg2-LDH was confirmed through the XRD, FTIR, and SEM. Fe/Mn/Mg2-LDH exhibited a good adsorption capacity towards Orange II and highly efficient PMS activation. The optimal removal efficiency of Orange II (98%) was achieved under the conditions of pH 7.0, [PMS] = 1.0 mmol L−1, [Fe/Mn/Mg₂-LDH] = 1.6 g L−1, and [Orange II] = 50 μM. Additionally, this system demonstrated good adaptability across a wide pH range. The presence of Cl− and humic acids (HA) did not significantly inhibit Orange II removal, whereas inhibitory effects were observed in the presence of CO32− and PO43−. The removal mechanism of Orange II was attributed to a synergy of adsorption and oxidation processes, wherein the generated surface radicals (SO4•−ads and HO•ads) on the surface of the Fe/Mn/Mg2-LDH played a predominant role. Furthermore, the Fe/Mn/Mg2-LDH exhibited good reusability, maintaining a removal rate of 90% over five cycles of recycling. The Fe/Mn/Mg2-LDH/PMS system shows promising potential for the treatment of wastewater contaminated with refractory organic pollutants.
{"title":"Enhanced Orange II Removal Using Fe/Mn/Mg2-LDH Activated Peroxymonosulfate: Synergistic Radical Oxidation and Adsorption","authors":"Yajie Wang, Cui Qiu, Peng Cheng, Yuqing Li, Yunlong Ma, Xiuzhen Tao, Bo Weng, Gilles Mailhot","doi":"10.3390/catal14060380","DOIUrl":"https://doi.org/10.3390/catal14060380","url":null,"abstract":"In this study, Fe/Mn/Mg2-LDH was utilized for the first time as a catalyst for peroxymonosulfate (PMS) activation to facilitate the removal of Orange II. This composite was characterized using various techniques, such as XRD, FTIR, SEM-EDS, BET, and XPS. The results revealed a well-defined lamellar structure of Fe/Mn/Mg2-LDH with a metal molar ratio of Fe/Mn/Mg at 1:1:2. Moreover, the structural stability of Fe/Mn/Mg2-LDH was confirmed through the XRD, FTIR, and SEM. Fe/Mn/Mg2-LDH exhibited a good adsorption capacity towards Orange II and highly efficient PMS activation. The optimal removal efficiency of Orange II (98%) was achieved under the conditions of pH 7.0, [PMS] = 1.0 mmol L−1, [Fe/Mn/Mg₂-LDH] = 1.6 g L−1, and [Orange II] = 50 μM. Additionally, this system demonstrated good adaptability across a wide pH range. The presence of Cl− and humic acids (HA) did not significantly inhibit Orange II removal, whereas inhibitory effects were observed in the presence of CO32− and PO43−. The removal mechanism of Orange II was attributed to a synergy of adsorption and oxidation processes, wherein the generated surface radicals (SO4•−ads and HO•ads) on the surface of the Fe/Mn/Mg2-LDH played a predominant role. Furthermore, the Fe/Mn/Mg2-LDH exhibited good reusability, maintaining a removal rate of 90% over five cycles of recycling. The Fe/Mn/Mg2-LDH/PMS system shows promising potential for the treatment of wastewater contaminated with refractory organic pollutants.","PeriodicalId":505577,"journal":{"name":"Catalysts","volume":"18 10","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141338955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dhanalakshmi Vadivel, Swetha Suryakumar, Claudio Casella, Andrea Speltini, Daniele Dondi
Materials science and catalysis advancements play a critical role in achieving sustainable development by managing environmental, energy, and resource challenges. Catalyst design advancements focus on enhancing selectivity to achieve sustainable chemical reactions, reducing energy consumption. Designing catalysts that are environmentally friendly and biodegradable is increasingly gaining importance. This aligns with the principles of green chemistry and contributes to minimizing the environmental impact of catalytic processes. These advances, taken as a whole, lead to more sustainable and efficient processes in industries ranging from energy production to pollutant removal, fueling the advancement toward a more sustainable future. Photochemistry, that is, the activation of a stable compound (catalyst) into the highly reactive excited state, is of particular importance, since photons—especially when they come from solar light—are a green and renewable resource. This review article has provided the overall idea of the photocatalysts and materials under green chemistry perspective from the standpoint of the concept of sustainable development.
{"title":"Advancements in Materials Science and Photocatalysts for Sustainable Development","authors":"Dhanalakshmi Vadivel, Swetha Suryakumar, Claudio Casella, Andrea Speltini, Daniele Dondi","doi":"10.3390/catal14060378","DOIUrl":"https://doi.org/10.3390/catal14060378","url":null,"abstract":"Materials science and catalysis advancements play a critical role in achieving sustainable development by managing environmental, energy, and resource challenges. Catalyst design advancements focus on enhancing selectivity to achieve sustainable chemical reactions, reducing energy consumption. Designing catalysts that are environmentally friendly and biodegradable is increasingly gaining importance. This aligns with the principles of green chemistry and contributes to minimizing the environmental impact of catalytic processes. These advances, taken as a whole, lead to more sustainable and efficient processes in industries ranging from energy production to pollutant removal, fueling the advancement toward a more sustainable future. Photochemistry, that is, the activation of a stable compound (catalyst) into the highly reactive excited state, is of particular importance, since photons—especially when they come from solar light—are a green and renewable resource. This review article has provided the overall idea of the photocatalysts and materials under green chemistry perspective from the standpoint of the concept of sustainable development.","PeriodicalId":505577,"journal":{"name":"Catalysts","volume":"33 10","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141344234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the relentless pursuit of sustainable energy solutions, the petroleum industry faces the imperative challenge of mitigating sulfur emissions. This comprehensive review scrutinizes Titanium Dioxide (TiO2) as an extraordinary catalyst, pushing the boundaries of desulfurization performance in petroleum refining. The abstract begins by underscoring the urgent need for advanced desulfurization technologies, driven by stringent environmental mandates and escalating global energy demands. The spotlight then shifts to the unparalleled physicochemical attributes of TiO2, showcasing its inherent advantages such as exceptional surface area, stability, and photocatalytic process. A profound exploration of TiO2’s catalytic mechanisms follows, unraveling its capacity to disintegrate stubborn sulfur–carbon bonds, thereby elevating desulfurization efficiency to unprecedented levels. This review meticulously dissects diverse forms of TiO2, ranging from nanoparticles to mesoporous structures, and provides a critical analysis of their respective strengths and limitations in catalyzing sulfur removal. Delving into operational nuances, this review examines the impact of temperature, pressure, and catalyst loading on TiO2 performance, offering crucial insights for optimizing desulfurization processes. The narrative then unfolds to explore cutting-edge developments in TiO2-based catalysts, encompassing ingenious modifications, composites, and hybrid materials designed to augment catalytic activity and selectivity. Anticipating the road ahead, this review contemplates the challenges and prospects of deploying TiO2 on an industrial scale, pointing toward avenues for future research and development. This abstract encapsulates a wealth of knowledge, serving as an indispensable resource for researchers, engineers, and policymakers navigating the dynamic landscape of sustainable petroleum refining. TiO2 emerges as a transformative force, propelling the industry toward cleaner, greener, and more efficient energy production.
{"title":"Review of TiO2 as Desulfurization Catalyst for Petroleum","authors":"Z. A. Hamza, Jamal J. Dawood, M. Jabbar","doi":"10.3390/catal14060381","DOIUrl":"https://doi.org/10.3390/catal14060381","url":null,"abstract":"In the relentless pursuit of sustainable energy solutions, the petroleum industry faces the imperative challenge of mitigating sulfur emissions. This comprehensive review scrutinizes Titanium Dioxide (TiO2) as an extraordinary catalyst, pushing the boundaries of desulfurization performance in petroleum refining. The abstract begins by underscoring the urgent need for advanced desulfurization technologies, driven by stringent environmental mandates and escalating global energy demands. The spotlight then shifts to the unparalleled physicochemical attributes of TiO2, showcasing its inherent advantages such as exceptional surface area, stability, and photocatalytic process. A profound exploration of TiO2’s catalytic mechanisms follows, unraveling its capacity to disintegrate stubborn sulfur–carbon bonds, thereby elevating desulfurization efficiency to unprecedented levels. This review meticulously dissects diverse forms of TiO2, ranging from nanoparticles to mesoporous structures, and provides a critical analysis of their respective strengths and limitations in catalyzing sulfur removal. Delving into operational nuances, this review examines the impact of temperature, pressure, and catalyst loading on TiO2 performance, offering crucial insights for optimizing desulfurization processes. The narrative then unfolds to explore cutting-edge developments in TiO2-based catalysts, encompassing ingenious modifications, composites, and hybrid materials designed to augment catalytic activity and selectivity. Anticipating the road ahead, this review contemplates the challenges and prospects of deploying TiO2 on an industrial scale, pointing toward avenues for future research and development. This abstract encapsulates a wealth of knowledge, serving as an indispensable resource for researchers, engineers, and policymakers navigating the dynamic landscape of sustainable petroleum refining. TiO2 emerges as a transformative force, propelling the industry toward cleaner, greener, and more efficient energy production.","PeriodicalId":505577,"journal":{"name":"Catalysts","volume":"51 16","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141339316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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