The oxidative coupling of methane (OCM) is a promising process for converting methane directly into more valuable ethane and ethylene. In this work, high time resolution online mass spectrometry was employed to track the OCM reaction over a commercial La2O3 catalyst, focusing on the effects of methane to oxygen ratio, gas hourly space velocity (GHSV), and the presence of H2O and CO in the feed gas on methane conversion and C2 yield. The results demonstrated that an optimized GHSV (44,640 to 93,000 mL·g−1·h−1) and methane to oxygen ratio (CH4/O2 = 3) would achieve the highest methane conversion and C2 yield at 740 °C. Furthermore, at a GHSV of 44,640 mL·g−1·h−1, the introduction of 1% H2O into the reaction mixture resulted in a twofold increase in C2 yield at 650 °C, while the addition of 1% CO led to a threefold increase in C2 yield at 550 °C. A model in which only the front-end catalyst is active was also developed to show excellent agreement with the experimental data. The relationship between catalytic performance and the effective catalyst position in the catalyst bed provides important insights into optimizing reactor design and operating conditions to maximize C2 yield and selectivity in the OCM reaction.
{"title":"Optimizing Methane Oxidative Coupling over La2O3: Kinetic and Product Analysis","authors":"Zhehao Qiu, Yulu Cai","doi":"10.3390/catal15050499","DOIUrl":"https://doi.org/10.3390/catal15050499","url":null,"abstract":"The oxidative coupling of methane (OCM) is a promising process for converting methane directly into more valuable ethane and ethylene. In this work, high time resolution online mass spectrometry was employed to track the OCM reaction over a commercial La2O3 catalyst, focusing on the effects of methane to oxygen ratio, gas hourly space velocity (GHSV), and the presence of H2O and CO in the feed gas on methane conversion and C2 yield. The results demonstrated that an optimized GHSV (44,640 to 93,000 mL·g−1·h−1) and methane to oxygen ratio (CH4/O2 = 3) would achieve the highest methane conversion and C2 yield at 740 °C. Furthermore, at a GHSV of 44,640 mL·g−1·h−1, the introduction of 1% H2O into the reaction mixture resulted in a twofold increase in C2 yield at 650 °C, while the addition of 1% CO led to a threefold increase in C2 yield at 550 °C. A model in which only the front-end catalyst is active was also developed to show excellent agreement with the experimental data. The relationship between catalytic performance and the effective catalyst position in the catalyst bed provides important insights into optimizing reactor design and operating conditions to maximize C2 yield and selectivity in the OCM reaction.","PeriodicalId":9794,"journal":{"name":"Catalysts","volume":"15 5","pages":"499-499"},"PeriodicalIF":0.0,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.mdpi.com/2073-4344/15/5/499/pdf?version=1747821333","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147333277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Electrocatalytic nitrate reduction reaction (NO3−RR) to ammonia (NH3) presents an alternative, sustainable approach to ammonia production. However, the existing catalysts suffer from poor NH3 yield under lower concentrations of NO3−, and the kinetic understanding of bimetal catalysis is lacking. In this study, a Co3O4–modified Cu2+1O nanowire (CoCuNWs) catalyst with a high specific surface area was synthesized to effectively produce NH3 from a 10 mM KNO3 basic solution. CoCuNWs demonstrated a high NH3 yield rate of 0.30 mmol h−1 cm−2 with an NH3 Faradaic efficiency (FE) of 96.7% at −0.2 V vs. RHE, which is 1.5 times higher than the bare Cu2+1O NWs. The synergistic effect between Co3O4 and Cu2+1O significantly enhanced both the nitrate conversion and ammonia yield. Importantly, it is revealed that the surface of CoCuNWs is kinetically more easily saturated with NO3− (NO2−) ions than that of Cu2+1O NWs, as evidenced by both the higher current density and the plateau occurring at higher NOx− concentrations. In addition, CoCuNWs exhibit a higher diffusion coefficient of NO3−, being 1.6 times higher than that of Cu2+1O NWs, which also indicates that the presence of Co3O4 could promote the diffusion and adsorption of NO3− on CoCuNWs. Moreover, the ATR–SEIRAS analysis was applied to illustrate the reduction pathway of NO3− to NH3 on CoCuNWs, which follows the formation of the key intermediate from *NO2−, *NO, *NH2OH to *NH3. This work presents a strategy for constructing dual–metal catalysts for NO3−RR and provides an insight to understand the catalysis from the perspective of the kinetics.
{"title":"Kinetic Understanding of the Enhanced Electroreduction of Nitrate to Ammonia for Co3O4–Modified Cu2+1O Nanowire Electrocatalyst","authors":"Hao Yu, Yan Shen, Jiahua Zhang, Hua Wang","doi":"10.3390/catal15050491","DOIUrl":"https://doi.org/10.3390/catal15050491","url":null,"abstract":"Electrocatalytic nitrate reduction reaction (NO3−RR) to ammonia (NH3) presents an alternative, sustainable approach to ammonia production. However, the existing catalysts suffer from poor NH3 yield under lower concentrations of NO3−, and the kinetic understanding of bimetal catalysis is lacking. In this study, a Co3O4–modified Cu2+1O nanowire (CoCuNWs) catalyst with a high specific surface area was synthesized to effectively produce NH3 from a 10 mM KNO3 basic solution. CoCuNWs demonstrated a high NH3 yield rate of 0.30 mmol h−1 cm−2 with an NH3 Faradaic efficiency (FE) of 96.7% at −0.2 V vs. RHE, which is 1.5 times higher than the bare Cu2+1O NWs. The synergistic effect between Co3O4 and Cu2+1O significantly enhanced both the nitrate conversion and ammonia yield. Importantly, it is revealed that the surface of CoCuNWs is kinetically more easily saturated with NO3− (NO2−) ions than that of Cu2+1O NWs, as evidenced by both the higher current density and the plateau occurring at higher NOx− concentrations. In addition, CoCuNWs exhibit a higher diffusion coefficient of NO3−, being 1.6 times higher than that of Cu2+1O NWs, which also indicates that the presence of Co3O4 could promote the diffusion and adsorption of NO3− on CoCuNWs. Moreover, the ATR–SEIRAS analysis was applied to illustrate the reduction pathway of NO3− to NH3 on CoCuNWs, which follows the formation of the key intermediate from *NO2−, *NO, *NH2OH to *NH3. This work presents a strategy for constructing dual–metal catalysts for NO3−RR and provides an insight to understand the catalysis from the perspective of the kinetics.","PeriodicalId":9794,"journal":{"name":"Catalysts","volume":"15 5","pages":"491-491"},"PeriodicalIF":0.0,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.mdpi.com/2073-4344/15/5/491/pdf?version=1747643001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147330690","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study addresses energy transition challenges through the development of NiCuCe catalysts for high-purity hydrogen production via methanol decomposition, with carbon deposition issues mitigated by CO2-assisted regeneration. As fossil fuel depletion advances and the urgency of climate change increases, methanol-derived hydrogen (CH3OH → CO + 2H2) emerges as a carbon-neutral alternative to conventional fossil fuel-based energy systems. The catalyst’s dual Cu2+/Ni2+ active sites facilitate selective C–O bond cleavage, achieving more than 80% methanol conversion at temperatures exceeding 280 °C without the need for fossil methane inputs. Crucially, CO2 gasification enables catalyst regeneration through the conversion of 90% carbon deposits into reusable media, circumventing energy-intensive combustion processes. This dual-function system couples carbon capture to hydrogen infrastructure, thereby stabilizing production while valorizing waste CO2. This innovation minimizes reliance on rare metals through efficient regeneration cycles, mitigating resource constraints during energy crises.
{"title":"Sustainable Hydrogen from Methanol: NiCuCe Catalyst Design with CO2-Driven Regeneration for Carbon-Neutral Energy Systems","authors":"Yankun Jiang, Liangdong Zhao, Siqi Li","doi":"10.3390/catal15050478","DOIUrl":"https://doi.org/10.3390/catal15050478","url":null,"abstract":"This study addresses energy transition challenges through the development of NiCuCe catalysts for high-purity hydrogen production via methanol decomposition, with carbon deposition issues mitigated by CO2-assisted regeneration. As fossil fuel depletion advances and the urgency of climate change increases, methanol-derived hydrogen (CH3OH → CO + 2H2) emerges as a carbon-neutral alternative to conventional fossil fuel-based energy systems. The catalyst’s dual Cu2+/Ni2+ active sites facilitate selective C–O bond cleavage, achieving more than 80% methanol conversion at temperatures exceeding 280 °C without the need for fossil methane inputs. Crucially, CO2 gasification enables catalyst regeneration through the conversion of 90% carbon deposits into reusable media, circumventing energy-intensive combustion processes. This dual-function system couples carbon capture to hydrogen infrastructure, thereby stabilizing production while valorizing waste CO2. This innovation minimizes reliance on rare metals through efficient regeneration cycles, mitigating resource constraints during energy crises.","PeriodicalId":9794,"journal":{"name":"Catalysts","volume":"15 5","pages":"478-478"},"PeriodicalIF":0.0,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.mdpi.com/2073-4344/15/5/478/pdf?version=1747116166","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147334041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shiqi Yuan, Yudong Huo, Ying Zhang, Lijie Xu, Lu Gan
Wastewater involving nitrogen-containing emerging contaminants is always accompanied by ammonia nitrogen. In this study, the 254 nm UV light activating peroxymonosulfate (PMS) process was investigated based on its performance and mechanisms for the simultaneous removal of carbamazepine (CBZ) and ammonia nitrogen. The results showed that both CBZ and ammonia could be simultaneously removed from water by the UV/PMS process, which was mainly attributed to the oxidation of SO4•− and •OH, respectively. Solution pH did not significantly affect CBZ degradation, but was a crucial factor for the removal of ammonia, and only the alkaline condition was effective for ammonia removal. The steady-state concentration of SO4•− (4.37 × 10−11 M) at pH 10.5 was determined as 32 times that of •OH (1.35 × 10−12 M), which made CBZ more competitive than ammonia in competing for radicals and more adaptable to coexisting anions. An appropriate increase in PMS concentration and light intensity could improve the removal of ammonia more significantly than that of CBZ, but an over-intense reaction could accelerate the decrease in solution pH, resulting in a plateau in ammonia removal. Moreover, the formation of nitrate and nitrogen gas was the primary transformation route of ammonia in the UV/PMS process. With the optimum PMS concentration of 2 mM, about 50% of the total nitrogen could be removed. The results of this study may provide some insights into applying the UV/PMS process for the simultaneous removal of emerging contaminants and ammonia nitrogen.
{"title":"Performance and Mechanism Study of Simultaneous Removal of Carbamazepine and Ammonia from Water Using UV/Peroxymonosulfate Process","authors":"Shiqi Yuan, Yudong Huo, Ying Zhang, Lijie Xu, Lu Gan","doi":"10.3390/catal15050468","DOIUrl":"https://doi.org/10.3390/catal15050468","url":null,"abstract":"Wastewater involving nitrogen-containing emerging contaminants is always accompanied by ammonia nitrogen. In this study, the 254 nm UV light activating peroxymonosulfate (PMS) process was investigated based on its performance and mechanisms for the simultaneous removal of carbamazepine (CBZ) and ammonia nitrogen. The results showed that both CBZ and ammonia could be simultaneously removed from water by the UV/PMS process, which was mainly attributed to the oxidation of SO4•− and •OH, respectively. Solution pH did not significantly affect CBZ degradation, but was a crucial factor for the removal of ammonia, and only the alkaline condition was effective for ammonia removal. The steady-state concentration of SO4•− (4.37 × 10−11 M) at pH 10.5 was determined as 32 times that of •OH (1.35 × 10−12 M), which made CBZ more competitive than ammonia in competing for radicals and more adaptable to coexisting anions. An appropriate increase in PMS concentration and light intensity could improve the removal of ammonia more significantly than that of CBZ, but an over-intense reaction could accelerate the decrease in solution pH, resulting in a plateau in ammonia removal. Moreover, the formation of nitrate and nitrogen gas was the primary transformation route of ammonia in the UV/PMS process. With the optimum PMS concentration of 2 mM, about 50% of the total nitrogen could be removed. The results of this study may provide some insights into applying the UV/PMS process for the simultaneous removal of emerging contaminants and ammonia nitrogen.","PeriodicalId":9794,"journal":{"name":"Catalysts","volume":"15 5","pages":"468-468"},"PeriodicalIF":0.0,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.mdpi.com/2073-4344/15/5/468/pdf?version=1746792399","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147331328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yameng Wang, Ao Xu, Jihui Lang, Bin Zuo, Zihan Yu, Keyu Cui, Xuefei Li, Kewei Zhang, Xin Li, Maobin Wei, Jian Cao, Maobin Wei, Jian Cao
CO2 photoreduction technology offers significant potential for addressing energy and environmental challenges, though its practical application is hindered by insufficient photo-absorption and rapid carrier recombination. Herein, we constructed the WO3/In2S3 S-scheme heterojunction through hydrothermal assembly of two-dimensional WO3 nanosheets and scale-like In2S3 nanoflakes. Systematic characterization via XRD, XPS, SEM, and TEM verified the successful preparation of hierarchical nanostructures with optimized interfacial contact in the WO3/In2S3 composites. UV-Vis DRS analysis showed that the photo-absorption range of the catalyst was significantly widened. Photoelectrochemical investigations (EIS, TPR, PL, and LSV) revealed enhanced carrier separation efficiency and reduced recombination kinetics in the heterojunction system. The optimized WO3/In2S3 (WI-60) catalyst had a CO evolution efficiency of 55.14 μmol·g−1 under the UV-Vis light, representing a 3.9-fold enhancement over the pure In2S3 (14.08 μmol·g−1). Mechanistic studies through the XPS and band-structure analysis confirmed the establishment of an S-scheme carrier’ transfer pathway, which simultaneously preserved strong redox potentials and promoted the separation process of carriers. This research provides a validated strategy for developing efficient S-scheme photocatalytic systems for solar fuel generation.
{"title":"Interfacial Engineering of S-Scheme WO3/In2S3 Heterojunction for Efficient Solar-Driven CO2 Photoreduction","authors":"Yameng Wang, Ao Xu, Jihui Lang, Bin Zuo, Zihan Yu, Keyu Cui, Xuefei Li, Kewei Zhang, Xin Li, Maobin Wei, Jian Cao, Maobin Wei, Jian Cao","doi":"10.3390/catal15050460","DOIUrl":"https://doi.org/10.3390/catal15050460","url":null,"abstract":"CO2 photoreduction technology offers significant potential for addressing energy and environmental challenges, though its practical application is hindered by insufficient photo-absorption and rapid carrier recombination. Herein, we constructed the WO3/In2S3 S-scheme heterojunction through hydrothermal assembly of two-dimensional WO3 nanosheets and scale-like In2S3 nanoflakes. Systematic characterization via XRD, XPS, SEM, and TEM verified the successful preparation of hierarchical nanostructures with optimized interfacial contact in the WO3/In2S3 composites. UV-Vis DRS analysis showed that the photo-absorption range of the catalyst was significantly widened. Photoelectrochemical investigations (EIS, TPR, PL, and LSV) revealed enhanced carrier separation efficiency and reduced recombination kinetics in the heterojunction system. The optimized WO3/In2S3 (WI-60) catalyst had a CO evolution efficiency of 55.14 μmol·g−1 under the UV-Vis light, representing a 3.9-fold enhancement over the pure In2S3 (14.08 μmol·g−1). Mechanistic studies through the XPS and band-structure analysis confirmed the establishment of an S-scheme carrier’ transfer pathway, which simultaneously preserved strong redox potentials and promoted the separation process of carriers. This research provides a validated strategy for developing efficient S-scheme photocatalytic systems for solar fuel generation.","PeriodicalId":9794,"journal":{"name":"Catalysts","volume":"15 5","pages":"460-460"},"PeriodicalIF":0.0,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.mdpi.com/2073-4344/15/5/460/pdf?version=1746697088","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147333375","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Weijie Chen, Bingbing Zhang, Hao Pu, Zhao Yang, Yixue Qin, Mingze An, Chengtao Gao, Kang Mao, Sheng Wang, Bing Xue, Chongwen Sun
Tetracycline (TC) contamination in wastewater presents a significant global environmental challenge, with conventional water treatment methods often proving ineffective at eliminating antibiotic pollutants. As a result, there is an urgent need for cost-effective and efficient remediation technologies. In this study, we utilized the abundant and low-cost Eichhornia crassipes as a precursor to prepare sulfuric acid-modified functional biochar (SC-Fe) through a two-step pyrolysis process. This SC-Fe was then employed to activate peroxydisulfate (PDS) for the removal of TC from wastewater. The structural and physicochemical properties of SC-Fe were extensively characterized, and its efficiency in activating PDS for TC degradation was evaluated. The results demonstrated that the SC-Fe/PDS system effectively removed 99.36% of TC within 60 min under optimal conditions (0.3 g/L SC-Fe, 5 mM PDS, initial pH 7.09, and 25 °C). The outstanding removal efficiency can be attributed to the high specific surface area, large porosity, and defect-rich structure of SC-Fe. Furthermore, during the TC removal process, the SC-Fe/PDS system generated SO4•−, •OH, and 1O2, with SO4•− and •OH acting as the primary reactive species. The high catalytic efficiency and low consumption of the SC-Fe/PDS system present a promising strategy for effective wastewater treatment.
废水中的四环素（TC）污染是一个重大的全球环境挑战，传统的水处理方法往往被证明在消除抗生素污染物方面是无效的。因此，迫切需要具有成本效益和效率的修复技术。在本研究中，我们利用丰富且低成本的石竹为前驱体，通过两步热解工艺制备硫酸改性功能生物炭（SC-Fe）。然后用SC-Fe活化过硫酸氢盐（PDS）去除废水中的TC。广泛表征了SC-Fe的结构和理化性质，并对其活化PDS降解TC的效率进行了评价。结果表明，在最佳条件（0.3 g/L SC-Fe, 5 mM PDS，初始pH为7.09,25°C）下，SC-Fe/PDS体系在60 min内有效去除99.36%的TC。SC-Fe具有高比表面积、大孔隙率和富含缺陷的结构，具有优异的去除率。此外，在TC去除过程中，SC-Fe/PDS体系生成SO4•−、•OH和1O2，其中SO4•−和•OH是主要的反应物质。SC-Fe/PDS系统具有高催化效率和低能耗的特点，是有效处理废水的一种很有前景的方法。
{"title":"Iron-Modified Functional Biochar Activates Peroxydisulfate for Efficient Degradation of Organic Pollutants","authors":"Weijie Chen, Bingbing Zhang, Hao Pu, Zhao Yang, Yixue Qin, Mingze An, Chengtao Gao, Kang Mao, Sheng Wang, Bing Xue, Chongwen Sun","doi":"10.3390/catal15050462","DOIUrl":"https://doi.org/10.3390/catal15050462","url":null,"abstract":"Tetracycline (TC) contamination in wastewater presents a significant global environmental challenge, with conventional water treatment methods often proving ineffective at eliminating antibiotic pollutants. As a result, there is an urgent need for cost-effective and efficient remediation technologies. In this study, we utilized the abundant and low-cost Eichhornia crassipes as a precursor to prepare sulfuric acid-modified functional biochar (SC-Fe) through a two-step pyrolysis process. This SC-Fe was then employed to activate peroxydisulfate (PDS) for the removal of TC from wastewater. The structural and physicochemical properties of SC-Fe were extensively characterized, and its efficiency in activating PDS for TC degradation was evaluated. The results demonstrated that the SC-Fe/PDS system effectively removed 99.36% of TC within 60 min under optimal conditions (0.3 g/L SC-Fe, 5 mM PDS, initial pH 7.09, and 25 °C). The outstanding removal efficiency can be attributed to the high specific surface area, large porosity, and defect-rich structure of SC-Fe. Furthermore, during the TC removal process, the SC-Fe/PDS system generated SO4•−, •OH, and 1O2, with SO4•− and •OH acting as the primary reactive species. The high catalytic efficiency and low consumption of the SC-Fe/PDS system present a promising strategy for effective wastewater treatment.","PeriodicalId":9794,"journal":{"name":"Catalysts","volume":"15 5","pages":"462-462"},"PeriodicalIF":0.0,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.mdpi.com/2073-4344/15/5/462/pdf?version=1746706040","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147333702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this work, the method of highly efficient conversion of l-rhamnose to 5-methylfurfural (MF) catalyzed by various catalysts in a biphasic system was developed. To enhance the MF yield, the effects of the catalyst species, reaction temperature (150–180 °C), extraction solvents and volume ratio of the extraction to the aqueous phase (0–5) on the conversion of l-rhamnose to MF were systematically investigated. Under optimal conditions, a high MF yield of 94% was achieved in the biphasic “diisopropyl ether (DIPE) + H2O” system due to the fact that the extraction of MF to the DIPE phase significantly inhibits the condensation and degradation of MF in water. Finally, detailed reaction energetics and chemical structures of intermediates of the l-rhamnose dehydration to MF were investigated using the B3LYP level of theory and the SMD solvation model. It is evident that MF, which exhibits excellent chemical stability, harbors the potential to function as a bio-derived platform chemical within the domain of the green industry.
{"title":"Efficient Method for the Synthesis of 5-Methylfurfural from l-Rhamnose Using a Biphasic System","authors":"Zongke He, Pengfei Jiang, Qianqian Cui, Ziyue Wang, Yaozhong Wei, Chao Luo, Jichang Guo, Chang Liu, Wei Zhang","doi":"10.3390/catal15050465","DOIUrl":"https://doi.org/10.3390/catal15050465","url":null,"abstract":"In this work, the method of highly efficient conversion of l-rhamnose to 5-methylfurfural (MF) catalyzed by various catalysts in a biphasic system was developed. To enhance the MF yield, the effects of the catalyst species, reaction temperature (150–180 °C), extraction solvents and volume ratio of the extraction to the aqueous phase (0–5) on the conversion of l-rhamnose to MF were systematically investigated. Under optimal conditions, a high MF yield of 94% was achieved in the biphasic “diisopropyl ether (DIPE) + H2O” system due to the fact that the extraction of MF to the DIPE phase significantly inhibits the condensation and degradation of MF in water. Finally, detailed reaction energetics and chemical structures of intermediates of the l-rhamnose dehydration to MF were investigated using the B3LYP level of theory and the SMD solvation model. It is evident that MF, which exhibits excellent chemical stability, harbors the potential to function as a bio-derived platform chemical within the domain of the green industry.","PeriodicalId":9794,"journal":{"name":"Catalysts","volume":"15 5","pages":"465-465"},"PeriodicalIF":0.0,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.mdpi.com/2073-4344/15/5/465/pdf?version=1746716670","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147332217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dan Sun, Zhihe Ma, Yuran Cheng, G XU, Le Huang, Tingzhi Zhou, Zuojun Wei, Yingxin Liu
Cyclohexylamines are important and valuable key intermediates in the chemical industry, playing a crucial role in the synthesis of a variety of compounds. Developing a low-cost and efficient synthesis route for these chemicals is highly desirable but also presents significant challenges due to the complexity of the reactions involved. Herein, we designed three pathways for the production of 1,3-cyclohexanediamine (1,3-CHDA), including the one-pot reductive amination of resorcinol (RES) with ammonia and molecular hydrogen, the reductive amination of 1,3-cyclohexandione (1,3-CHD) with ammonia, and the oximation–hydrogenation of 1,3-CHD. Through systematical investigation, we finally developed a low-cost, simple operation and an efficient methodology for the synthesis of 1,3-CHDA as follows: RES was firstly hydrogenated in H2O over Raney Ni to obtain 1,3-CHD, and then the obtained liquid reaction mixture was used directly for the subsequent oximation with hydroxylamine hydrochloride without further purification to form the oxime intermediate, followed by the hydrogenation of the oxime in methanol over Raney Ni to achieve the target product 1,3-CHDA with a high yield.
{"title":"Designing a Potential Pathway for the Catalytic Synthesis of 1,3-Cyclohexanediamine","authors":"Dan Sun, Zhihe Ma, Yuran Cheng, G XU, Le Huang, Tingzhi Zhou, Zuojun Wei, Yingxin Liu","doi":"10.3390/catal15050446","DOIUrl":"https://doi.org/10.3390/catal15050446","url":null,"abstract":"Cyclohexylamines are important and valuable key intermediates in the chemical industry, playing a crucial role in the synthesis of a variety of compounds. Developing a low-cost and efficient synthesis route for these chemicals is highly desirable but also presents significant challenges due to the complexity of the reactions involved. Herein, we designed three pathways for the production of 1,3-cyclohexanediamine (1,3-CHDA), including the one-pot reductive amination of resorcinol (RES) with ammonia and molecular hydrogen, the reductive amination of 1,3-cyclohexandione (1,3-CHD) with ammonia, and the oximation–hydrogenation of 1,3-CHD. Through systematical investigation, we finally developed a low-cost, simple operation and an efficient methodology for the synthesis of 1,3-CHDA as follows: RES was firstly hydrogenated in H2O over Raney Ni to obtain 1,3-CHD, and then the obtained liquid reaction mixture was used directly for the subsequent oximation with hydroxylamine hydrochloride without further purification to form the oxime intermediate, followed by the hydrogenation of the oxime in methanol over Raney Ni to achieve the target product 1,3-CHDA with a high yield.","PeriodicalId":9794,"journal":{"name":"Catalysts","volume":"15 5","pages":"446-446"},"PeriodicalIF":0.0,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.mdpi.com/2073-4344/15/5/446/pdf?version=1746175298","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147332589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Qikai Huang, Xu Zhang, Tong Li, Yipu Liu, Shiwei Lin
The design of efficient hydrogen evolution reaction (HER) catalysts to minimize reaction overpotentials plays a pivotal role in advancing water electrolysis and clean energy solutions. Ru-based catalysts, regarded as potential replacements for Pt-based catalysts, face stability challenges during catalytic process. The precise regulation of metal–support interactions effectively prevents Ru nanoparticle degradation while optimizing interfacial electronic properties, enabling the simultaneous enhancement of catalytic activity and stability. Herein, we design an amorphous/crystalline support and employ in situ replacement to develop a Ru-NiPx-Ni structure. The crystalline Ni phase with ordered atomic arrangement ensures efficient charge transport, while the amorphous phase with unsaturated dangling bonds provides abundant anchoring sites for Ru nanoclusters. This synergistic structure significantly enhances HER performance, which attains overpotentials of 19 mV at 10 mA cm−2 and 70 mV at 100 mA cm−2 in 1 m KOH, with sustained operation exceeding 55 h at 100 mA cm−2. Electrochemical impedance spectroscopy analysis confirms that the Ru-NiPx-Ni structure not only has a high density of active centers for HER, but also reduces the charge transfer resistance at the electrode–electrolyte interface, which effectively enhances HER kinetics. This study presents new directions for designing high-efficiency HER catalysts.
设计高效析氢反应（HER）催化剂以降低反应过电位在推进水电解和清洁能源解决方案中发挥着关键作用。钌基催化剂作为pt基催化剂的潜在替代品，在催化过程中面临着稳定性的挑战。金属-载体相互作用的精确调控有效地防止了Ru纳米颗粒的降解，同时优化了界面电子性能，使催化活性和稳定性同时增强。在此，我们设计了一种非晶/晶体支架，并采用原位替换来开发Ru-NiPx-Ni结构。原子有序排列的结晶Ni相保证了高效的电荷传输，而具有不饱和悬空键的非晶态相为Ru纳米团簇提供了丰富的锚定位点。这种协同结构显著提高了HER性能，在1 m KOH条件下，在10 mA cm - 2条件下达到19 mV过电位，在100 mA cm - 2条件下达到70 mV过电位，在100 mA cm - 2条件下持续工作超过55小时。电化学阻抗谱分析证实，Ru-NiPx-Ni结构不仅具有高密度的HER活性中心，而且降低了电极-电解质界面处的电荷转移阻力，有效地提高了HER动力学。本研究为高效HER催化剂的设计提供了新的方向。
{"title":"Growing Nanocrystalline Ru on Amorphous/Crystalline Heterostructure for Efficient and Durable Hydrogen Evolution Reaction","authors":"Qikai Huang, Xu Zhang, Tong Li, Yipu Liu, Shiwei Lin","doi":"10.3390/catal15050434","DOIUrl":"https://doi.org/10.3390/catal15050434","url":null,"abstract":"The design of efficient hydrogen evolution reaction (HER) catalysts to minimize reaction overpotentials plays a pivotal role in advancing water electrolysis and clean energy solutions. Ru-based catalysts, regarded as potential replacements for Pt-based catalysts, face stability challenges during catalytic process. The precise regulation of metal–support interactions effectively prevents Ru nanoparticle degradation while optimizing interfacial electronic properties, enabling the simultaneous enhancement of catalytic activity and stability. Herein, we design an amorphous/crystalline support and employ in situ replacement to develop a Ru-NiPx-Ni structure. The crystalline Ni phase with ordered atomic arrangement ensures efficient charge transport, while the amorphous phase with unsaturated dangling bonds provides abundant anchoring sites for Ru nanoclusters. This synergistic structure significantly enhances HER performance, which attains overpotentials of 19 mV at 10 mA cm−2 and 70 mV at 100 mA cm−2 in 1 m KOH, with sustained operation exceeding 55 h at 100 mA cm−2. Electrochemical impedance spectroscopy analysis confirms that the Ru-NiPx-Ni structure not only has a high density of active centers for HER, but also reduces the charge transfer resistance at the electrode–electrolyte interface, which effectively enhances HER kinetics. This study presents new directions for designing high-efficiency HER catalysts.","PeriodicalId":9794,"journal":{"name":"Catalysts","volume":"15 5","pages":"434-434"},"PeriodicalIF":0.0,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.mdpi.com/2073-4344/15/5/434/pdf?version=1745916328","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147333136","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, a Brönsted–Lewis bifunctional acidic catalyst PW/UiO/CNTs-OH was synthesized via the hydrothermal method. The parameters for the esterification reaction of oleic acid with methanol catalyzed by PW/UiO/CNTs-OH were optimized using central composite design-response surface methodology (CCD-RSM). A biodiesel yield of 92.9% was achieved under the optimized conditions, retaining 82.3% biodiesel yield after four catalytic cycles. The enhanced catalytic performance of PW/UiO/CNTs-OH can be attributed as follows: the [Zr6O4(OH)4]12+ anchored on the surface of multi-walled carbon nanotubes (MWCNTs) can serve as nucleation sites for UiO-66, not only encapsulating H3[P(W3O10)4] (HPW) but also reversing the quadrupole moment of MWCNTs to generate Lewis acid sites. In addition, introduction of HPW during synthesis of UiO-66 decreases the solution pH, inducing the protonation of p-phthalic acid (PTA) to disrupt the coordination with the [Zr6O4(OH)4] cluster, thereby creating an unsaturated Zr4+ site with electron pair-accepting capability, which generates Lewis acid sites. EIS analysis revealed that PW/UiO/CNTs-OH has higher electron migration efficiency than UiO-66 and PW/UiO. Furthermore, NH3-TPD and Py-IR analyses showed that PW/UiO/CNTs-OH possessed high densities of Lewis acidic sites of 83.69 μmol/g and Brönsted acidic sites of 9.98 μmol/g.
{"title":"Response Surface Optimization of Biodiesel Production via Esterification Reaction of Methanol and Oleic Acid Catalyzed by a Brönsted–Lewis Catalyst PW/UiO/CNTs-OH","authors":"Xuyao Xing, Qiong Wu, Liqiang Zhang, Qing Shu","doi":"10.3390/catal15050412","DOIUrl":"https://doi.org/10.3390/catal15050412","url":null,"abstract":"In this study, a Brönsted–Lewis bifunctional acidic catalyst PW/UiO/CNTs-OH was synthesized via the hydrothermal method. The parameters for the esterification reaction of oleic acid with methanol catalyzed by PW/UiO/CNTs-OH were optimized using central composite design-response surface methodology (CCD-RSM). A biodiesel yield of 92.9% was achieved under the optimized conditions, retaining 82.3% biodiesel yield after four catalytic cycles. The enhanced catalytic performance of PW/UiO/CNTs-OH can be attributed as follows: the [Zr6O4(OH)4]12+ anchored on the surface of multi-walled carbon nanotubes (MWCNTs) can serve as nucleation sites for UiO-66, not only encapsulating H3[P(W3O10)4] (HPW) but also reversing the quadrupole moment of MWCNTs to generate Lewis acid sites. In addition, introduction of HPW during synthesis of UiO-66 decreases the solution pH, inducing the protonation of p-phthalic acid (PTA) to disrupt the coordination with the [Zr6O4(OH)4] cluster, thereby creating an unsaturated Zr4+ site with electron pair-accepting capability, which generates Lewis acid sites. EIS analysis revealed that PW/UiO/CNTs-OH has higher electron migration efficiency than UiO-66 and PW/UiO. Furthermore, NH3-TPD and Py-IR analyses showed that PW/UiO/CNTs-OH possessed high densities of Lewis acidic sites of 83.69 μmol/g and Brönsted acidic sites of 9.98 μmol/g.","PeriodicalId":9794,"journal":{"name":"Catalysts","volume":"15 5","pages":"412-412"},"PeriodicalIF":0.0,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.mdpi.com/2073-4344/15/5/412/pdf?version=1745390586","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147333699","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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