Yacine Boudjema , Antoine Brunel , Raphaël Del Cerro , Gerhard Pirngruber , Céline Chizallet , Kim Larmier
Sn-β is a promising Lewis acid zeolite for carbohydrate conversion. This material can be prepared either directly by hydrothermal synthesis or by a dealumination – metal incorporation sequence starting from a pre-made zeolite (post-synthesis modification). The synthesis method and the metallic precursors significantly influence the formation of Lewis acid sites in the zeolite, which is the primary factor determining the activity of the catalyst in many reactions. We synthesized various materials through post-synthesis modifications and a hydrothermal method using three different precursors. Pyridine adsorption monitored by FTIR spectroscopy shows that Sn-β samples synthesized by solid state insertion with tin chloride as a precursor feature a concentration of Lewis acid sites proportional to the tin content (up to 1.5 wt% of tin) without forming an oxide phase. Hydrothermal synthesis leads to a sample exhibiting weaker acid sites. The catalyst yields three major products in glucose conversion: fructose, mannose, and lactic acid. The high yield of lactic acid (≈30%) indicates a faster ketose retro-aldolization compared to aldose (no C4 or C2 products detected).
{"title":"Relationship between Lewis acid sites and carbohydrate reactivity over Sn-β catalysts†","authors":"Yacine Boudjema , Antoine Brunel , Raphaël Del Cerro , Gerhard Pirngruber , Céline Chizallet , Kim Larmier","doi":"10.1039/d4cy01147c","DOIUrl":"10.1039/d4cy01147c","url":null,"abstract":"<div><div>Sn-β is a promising Lewis acid zeolite for carbohydrate conversion. This material can be prepared either directly by hydrothermal synthesis or by a dealumination – metal incorporation sequence starting from a pre-made zeolite (post-synthesis modification). The synthesis method and the metallic precursors significantly influence the formation of Lewis acid sites in the zeolite, which is the primary factor determining the activity of the catalyst in many reactions. We synthesized various materials through post-synthesis modifications and a hydrothermal method using three different precursors. Pyridine adsorption monitored by FTIR spectroscopy shows that Sn-β samples synthesized by solid state insertion with tin chloride as a precursor feature a concentration of Lewis acid sites proportional to the tin content (up to 1.5 wt% of tin) without forming an oxide phase. Hydrothermal synthesis leads to a sample exhibiting weaker acid sites. The catalyst yields three major products in glucose conversion: fructose, mannose, and lactic acid. The high yield of lactic acid (≈30%) indicates a faster ketose retro-aldolization compared to aldose (no C4 or C2 products detected).</div></div>","PeriodicalId":66,"journal":{"name":"Catalysis Science & Technology","volume":"15 2","pages":"Pages 396-404"},"PeriodicalIF":4.4,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142993927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shigen Watanabe , Hideyuki Katsumata , Monir Uzzaman , Ikki Tateishi , Mai Furukawa , Satoshi Kaneco
Graphitic carbon nitride (g-CN) has attracted interest due to its cost-effectiveness, ease of synthesis, and suitable band structure for hydrogen evolution. However, its application is limited by high charge recombination rates and restricted visible light absorption, which lower photocatalytic performance. This study presents a modified g-CN catalyst, termed UPDB, incorporating π-conjugated and donor–acceptor (DA) structures using urea, 2,4,6-triaminopyrimidine (P), and dibenzothiophene-2-carboxaldehyde (DB). DRS and PL measurements revealed that alongside the π–π* transitions originating from pristine g-CN, UPDB exhibits n–π* transitions influenced by the lone pair electrons and unpaired electrons present in P and DB. This interaction creates a new absorption band (midgap) that broadens visible-light absorption. FT-IR analysis confirmed that the electron donor DB binds to the end of the g-CN backbone, while DFT calculations suggested that DB induces a spatial separation between the HOMO and LUMO, significantly decreasing charge recombination. At the optimal dosage, the hydrogen evolution rate of UPDB-10 (U (10 g), P (10 mg), and DB (1 mg)) reached 1000 μmol g−1 h−1, which was approximately 10 times higher than that of the original carbon nitride (U) calcined from urea alone. Furthermore, the apparent quantum yield (AQY) was 13.7% at 400 nm, 15.5% at 420 nm, and 6.3% at 450 nm in the presence of K2HPO4 (KPH), demonstrating high visible-light responsivity. The one-pot calcination method used in this study to introduce π-conjugation and a DA structure provides a novel approach to overcome the limitations of g-CN, paving the way for the advancement of solar energy conversion technology.
{"title":"Accelerated photocatalytic hydrogen evolution over donor–acceptor type graphitic carbon nitride (g-CN) with simultaneous modification of pyrimidine and thiophene rings†","authors":"Shigen Watanabe , Hideyuki Katsumata , Monir Uzzaman , Ikki Tateishi , Mai Furukawa , Satoshi Kaneco","doi":"10.1039/d4cy01401d","DOIUrl":"10.1039/d4cy01401d","url":null,"abstract":"<div><div>Graphitic carbon nitride (g-CN) has attracted interest due to its cost-effectiveness, ease of synthesis, and suitable band structure for hydrogen evolution. However, its application is limited by high charge recombination rates and restricted visible light absorption, which lower photocatalytic performance. This study presents a modified g-CN catalyst, termed UPDB, incorporating π-conjugated and donor–acceptor (DA) structures using urea, 2,4,6-triaminopyrimidine (P), and dibenzothiophene-2-carboxaldehyde (DB). DRS and PL measurements revealed that alongside the π–π* transitions originating from pristine g-CN, UPDB exhibits n–π* transitions influenced by the lone pair electrons and unpaired electrons present in P and DB. This interaction creates a new absorption band (midgap) that broadens visible-light absorption. FT-IR analysis confirmed that the electron donor DB binds to the end of the g-CN backbone, while DFT calculations suggested that DB induces a spatial separation between the HOMO and LUMO, significantly decreasing charge recombination. At the optimal dosage, the hydrogen evolution rate of UPDB-10 (U (10 g), P (10 mg), and DB (1 mg)) reached 1000 μmol g<sup>−1</sup> h<sup>−1</sup>, which was approximately 10 times higher than that of the original carbon nitride (U) calcined from urea alone. Furthermore, the apparent quantum yield (AQY) was 13.7% at 400 nm, 15.5% at 420 nm, and 6.3% at 450 nm in the presence of K<sub>2</sub>HPO<sub>4</sub> (KPH), demonstrating high visible-light responsivity. The one-pot calcination method used in this study to introduce π-conjugation and a DA structure provides a novel approach to overcome the limitations of g-CN, paving the way for the advancement of solar energy conversion technology.</div></div>","PeriodicalId":66,"journal":{"name":"Catalysis Science & Technology","volume":"15 2","pages":"Pages 416-426"},"PeriodicalIF":4.4,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142993929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The efficient conversion of methane to value-added compounds continues to be a challenging topic in the chemical industry. The industrial preparation of HCN requires methane and ammonia at high temperatures (>1000 °C) using precious metal Pt as a catalyst. The comprehensive understanding of the crucial role Pt plays therein has been obtained via concerted gas-phase and condensed-phase investigations. Alternatively, it is possible to inject high-quality energy into the reaction system using plasma technology to convert methane and ammonia to HCN under mild conditions. The selectivity and conversion of this process need further improvement toward industrial application, while the associated fundamental research is also needed in this area. In this perspective, we review the progress in the preparation of HCN from methane, including industrial processes and the newly emerging plasma catalysis, and have a look at the future of plasma-assisted methane conversion to HCN.
{"title":"Plasma-assisted methane conversion to HCN: the prospect and challenges","authors":"Na Ning , Chao Qian , Shaodong Zhou","doi":"10.1039/d4cy01239a","DOIUrl":"10.1039/d4cy01239a","url":null,"abstract":"<div><div>The efficient conversion of methane to value-added compounds continues to be a challenging topic in the chemical industry. The industrial preparation of HCN requires methane and ammonia at high temperatures (>1000 °C) using precious metal Pt as a catalyst. The comprehensive understanding of the crucial role Pt plays therein has been obtained <em>via</em> concerted gas-phase and condensed-phase investigations. Alternatively, it is possible to inject high-quality energy into the reaction system using plasma technology to convert methane and ammonia to HCN under mild conditions. The selectivity and conversion of this process need further improvement toward industrial application, while the associated fundamental research is also needed in this area. In this perspective, we review the progress in the preparation of HCN from methane, including industrial processes and the newly emerging plasma catalysis, and have a look at the future of plasma-assisted methane conversion to HCN.</div></div>","PeriodicalId":66,"journal":{"name":"Catalysis Science & Technology","volume":"15 2","pages":"Pages 249-261"},"PeriodicalIF":4.4,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142993970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yuting Feng , Qing Mao , Hongbin Yang , Wei Zhou , Dengye Yang , Yanfei Gao
The CO2 electrocatalytic reduction reaction (CO2RR) is currently an effective strategy for mitigating excessive global carbon dioxide emissions and accelerating the carbon cycle. Nonetheless, there are still significant obstacles to develop CO2RR catalysts with superior activity and excellent selectivity. Herein, we report a porous nitrogen-doped carbon material (Ni/NC-x) with high content of Ni–Nx units prepared by hydrothermal and pyrolytic methods. The content of Ni–Nx in Ni/NC-x samples was controlled by finely adjusting the proportion of additive PVP. The optimized Ni/NC-2 : 1 catalyst showed a CO partial current density (jCO) of 46.88 mA cm−2 and a CO faradaic efficiency (FECO) of up to 96% at −0.73 V vs. RHE; a FECO of 88% can be maintained in the flow cell while achieving jCO of 273.63 mA cm−2. Analysis through a thermodynamic–kinetic mechanism model suggests that the bifunctional Ni–Nx sites help to reduce the barrier of CO2 chemisorption and provide sufficient *CO2 for electron transfer during the reaction, hence enhancing the kinetics of CO2RR processes.
二氧化碳电催化还原反应（CO2RR）是目前缓解全球二氧化碳过量排放和加速碳循环的有效策略。尽管如此，开发具有优异活性和选择性的CO2RR催化剂仍然存在重大障碍。本文报道了一种通过水热法和热解法制备的具有高含量Ni - nx单元的多孔氮掺杂碳材料（Ni/NC-x）。通过精细调节添加剂PVP的比例来控制Ni/NC-x样品中Ni - nx的含量。优化后的Ni/NC-2: 1催化剂在−0.73 V时CO的偏电流密度（jCO）为46.88 mA cm−2，CO的法拉第效率（FECO）高达96%；在获得273.63 mA cm−2的jCO时，可保持88%的FECO。通过热力学动力学模型分析表明，双功能Ni-Nx位点有助于降低CO2的化学吸附障碍，并在反应过程中为电子传递提供足够的*CO2，从而增强了CO2RR过程的动力学。
{"title":"Ni single atom catalyst with high Ni–Nx content for efficient electrocatalytic reduction of CO2†","authors":"Yuting Feng , Qing Mao , Hongbin Yang , Wei Zhou , Dengye Yang , Yanfei Gao","doi":"10.1039/d4cy01249f","DOIUrl":"10.1039/d4cy01249f","url":null,"abstract":"<div><div>The CO<sub>2</sub> electrocatalytic reduction reaction (CO<sub>2</sub>RR) is currently an effective strategy for mitigating excessive global carbon dioxide emissions and accelerating the carbon cycle. Nonetheless, there are still significant obstacles to develop CO<sub>2</sub>RR catalysts with superior activity and excellent selectivity. Herein, we report a porous nitrogen-doped carbon material (Ni/NC-<em>x</em>) with high content of Ni–N<sub><em>x</em></sub> units prepared by hydrothermal and pyrolytic methods. The content of Ni–N<sub><em>x</em></sub> in Ni/NC-<em>x</em> samples was controlled by finely adjusting the proportion of additive PVP. The optimized Ni/NC-2 : 1 catalyst showed a CO partial current density (<em>j</em><sub>CO</sub>) of 46.88 mA cm<sup>−2</sup> and a CO faradaic efficiency (FE<sub>CO</sub>) of up to 96% at −0.73 V <em>vs.</em> RHE; a FE<sub>CO</sub> of 88% can be maintained in the flow cell while achieving <em>j</em><sub>CO</sub> of 273.63 mA cm<sup>−2</sup>. Analysis through a thermodynamic–kinetic mechanism model suggests that the bifunctional Ni–N<sub><em>x</em></sub> sites help to reduce the barrier of CO<sub>2</sub> chemisorption and provide sufficient *CO<sub>2</sub> for electron transfer during the reaction, hence enhancing the kinetics of CO<sub>2</sub>RR processes.</div></div>","PeriodicalId":66,"journal":{"name":"Catalysis Science & Technology","volume":"15 2","pages":"Pages 514-522"},"PeriodicalIF":4.4,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142992829","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lin Li , Hao Li , Huan Li , Wenhui Ding , Jianping Xiao
Aromatic hydrocarbons are essential petrochemical intermediates traditionally produced through naphtha reforming, where feedstock costs account for a substantial portion of total manufacturing expenses. Expanding the range of raw materials for aromatics production is therefore highly desirable. The direct utilization of CO2 or co-conversion with the abundant light alkanes from shale gas to produce aromatic hydrocarbons has both environmental and economic advantages in terms of reducing greenhouse gases and aromatics production costs. In this perspective, we have reviewed two CO2-based pathways for aromatics synthesis over zeolites: direct CO2-to-aromatics conversion, and CO2-oxidative dehydrogenation and aromatization pathways. CO2 utilization for aromatics synthesis was discussed from the viewpoints of catalyst components, active sites, and the role of CO2 in reaction mechanisms, as well as aromatics selectivity regulation. Lastly, we proposed the challenges and opportunities that lie ahead for advancing aromatics production with the utilization of CO2.
{"title":"CO2 utilization for aromatics synthesis over zeolites","authors":"Lin Li , Hao Li , Huan Li , Wenhui Ding , Jianping Xiao","doi":"10.1039/d4cy01434k","DOIUrl":"10.1039/d4cy01434k","url":null,"abstract":"<div><div>Aromatic hydrocarbons are essential petrochemical intermediates traditionally produced through naphtha reforming, where feedstock costs account for a substantial portion of total manufacturing expenses. Expanding the range of raw materials for aromatics production is therefore highly desirable. The direct utilization of CO<sub>2</sub> or co-conversion with the abundant light alkanes from shale gas to produce aromatic hydrocarbons has both environmental and economic advantages in terms of reducing greenhouse gases and aromatics production costs. In this perspective, we have reviewed two CO<sub>2</sub>-based pathways for aromatics synthesis over zeolites: direct CO<sub>2</sub>-to-aromatics conversion, and CO<sub>2</sub>-oxidative dehydrogenation and aromatization pathways. CO<sub>2</sub> utilization for aromatics synthesis was discussed from the viewpoints of catalyst components, active sites, and the role of CO<sub>2</sub> in reaction mechanisms, as well as aromatics selectivity regulation. Lastly, we proposed the challenges and opportunities that lie ahead for advancing aromatics production with the utilization of CO<sub>2</sub>.</div></div>","PeriodicalId":66,"journal":{"name":"Catalysis Science & Technology","volume":"15 2","pages":"Pages 234-248"},"PeriodicalIF":4.4,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142993969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tshepo Molefe , Roy Peter Forbes , Neil John Coville
Spillover effects from an easily reduced metal (Os) to a less easily reduced metal (Co) were investigated by use of hollow carbon spheres (HCSs) of different shell thicknesses, x, (x = 16 nm, 28 nm and 51 nm). The Co (10%) was loaded inside the HCS and the Os (1%) outside three HCS supports (Os/Co@HCSx). Temperature programmed reduction, together with BET and XRD studies, were used to monitor the effects of the Os on the Co as a function of HCS shell thickness. When no Os was present on the outside of the HCSs, the effect of H2 diffusion on the two Co reduction peaks was determined. Comparison with the Os containing Co@HCSs catalysts indicated that the two Co reduction peaks were influenced differently by the HCS shell thickness. Spillover of hydrogen could be observed at distances of ca. >100 nm, as shown by the shift of the first Co reduction peak (Co3O4 to CoO) while that of the second reduction peak (CoO to Co) was only observed at distances up to ca. 50 nm. The disordered carbon material is proposed to be responsible for the H transfer reaction between Os and Co. The Os/(Co@HCSx) catalysts were tested for Fischer–Tropsch (FT) activity and the data indicated a drop in the FT activity with shell thickness. This suggests that HCSs require an optimum thickness (to provide stability, good porosity and auto-reduction behaviour) to generate high FT activity/selectivity, with spillover effects aiding the reaction.
{"title":"The effect of separation distance on hydrogen spillover in Os promoted Co@HCS catalysts†","authors":"Tshepo Molefe , Roy Peter Forbes , Neil John Coville","doi":"10.1039/d4cy00758a","DOIUrl":"10.1039/d4cy00758a","url":null,"abstract":"<div><div>Spillover effects from an easily reduced metal (Os) to a less easily reduced metal (Co) were investigated by use of hollow carbon spheres (HCSs) of different shell thicknesses, <em>x</em>, (<em>x</em> = 16 nm, 28 nm and 51 nm). The Co (10%) was loaded inside the HCS and the Os (1%) outside three HCS supports (Os/Co@HCS<em>x</em>). Temperature programmed reduction, together with BET and XRD studies, were used to monitor the effects of the Os on the Co as a function of HCS shell thickness. When no Os was present on the outside of the HCSs, the effect of H<sub>2</sub> diffusion on the two Co reduction peaks was determined. Comparison with the Os containing Co@HCSs catalysts indicated that the two Co reduction peaks were influenced differently by the HCS shell thickness. Spillover of hydrogen could be observed at distances of <em>ca.</em> >100 nm, as shown by the shift of the first Co reduction peak (Co<sub>3</sub>O<sub>4</sub> to CoO) while that of the second reduction peak (CoO to Co) was only observed at distances up to <em>ca.</em> 50 nm. The disordered carbon material is proposed to be responsible for the H transfer reaction between Os and Co. The Os/(Co@HCS<em>x</em>) catalysts were tested for Fischer–Tropsch (FT) activity and the data indicated a drop in the FT activity with shell thickness. This suggests that HCSs require an optimum thickness (to provide stability, good porosity and auto-reduction behaviour) to generate high FT activity/selectivity, with spillover effects aiding the reaction.</div></div>","PeriodicalId":66,"journal":{"name":"Catalysis Science & Technology","volume":"15 2","pages":"Pages 334-343"},"PeriodicalIF":4.4,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/cy/d4cy00758a?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142993923","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, a noble metal-free and recyclable NiCuFe2O4 nanoparticle was developed via a one-pot co-precipitation approach. The synthesized nanoparticle was characterized by various sophisticated techniques such as SEM, EDX, VSM, PXRD, XPS, BET, ICP-AES, ICP-MS, elemental mapping and TEM analyses to gain detailed insights about its physiochemical properties. Electron microscopy studies validate the formation of hierarchical nanosphere morphology of the as-synthesized NiCuFe2O4 nanoparticles, while VSM analysis highlights their ferromagnetic nature. Powder X-ray diffraction reveals that Cu replaces Ni in the face-centered cubic lattice, causing a shift in peak positions as well as an increase in the lattice parameter with reduced Ni content. This cost-effective and magnetically separable NiCuFe2O4 nanostructure holds promise as a potential substitute for Pd-based catalysts in Suzuki–Miyaura cross-coupling of arylboronic acid with various substituents of aryl halide. Notably, they demonstrate remarkable catalytic activity in producing biaryl scaffolds by effectively activating not only Ar–Br bonds but also chemically inert Ar–Cl and Ar–F bonds under mild conditions in ethanol–water media, outperforming most of the reported works involving transition metal-based catalysts. These heterogenous catalysts have the tendency to retain their activity up to the fifth iterations during the reaction with a broad substrate scope, providing significant economic advantages for industrial applications.
{"title":"Sustainable fabrication of NiCuFe2O4 nanospheres: a highly effective palladium-free heterogeneous catalyst for biaryl scaffold synthesis via a Suzuki–Miyaura cross-coupling reaction†","authors":"Tikendrajit Chetia , Amar Jyoti Kalita , Aquif Suleman , Bolin Chetia","doi":"10.1039/d4cy01100g","DOIUrl":"10.1039/d4cy01100g","url":null,"abstract":"<div><div>In this work, a noble metal-free and recyclable NiCuFe<sub>2</sub>O<sub>4</sub> nanoparticle was developed <em>via</em> a one-pot co-precipitation approach. The synthesized nanoparticle was characterized by various sophisticated techniques such as SEM, EDX, VSM, PXRD, XPS, BET, ICP-AES, ICP-MS, elemental mapping and TEM analyses to gain detailed insights about its physiochemical properties. Electron microscopy studies validate the formation of hierarchical nanosphere morphology of the as-synthesized NiCuFe<sub>2</sub>O<sub>4</sub> nanoparticles, while VSM analysis highlights their ferromagnetic nature. Powder X-ray diffraction reveals that Cu replaces Ni in the face-centered cubic lattice, causing a shift in peak positions as well as an increase in the lattice parameter with reduced Ni content. This cost-effective and magnetically separable NiCuFe<sub>2</sub>O<sub>4</sub> nanostructure holds promise as a potential substitute for Pd-based catalysts in Suzuki–Miyaura cross-coupling of arylboronic acid with various substituents of aryl halide. Notably, they demonstrate remarkable catalytic activity in producing biaryl scaffolds by effectively activating not only Ar–Br bonds but also chemically inert Ar–Cl and Ar–F bonds under mild conditions in ethanol–water media, outperforming most of the reported works involving transition metal-based catalysts. These heterogenous catalysts have the tendency to retain their activity up to the fifth iterations during the reaction with a broad substrate scope, providing significant economic advantages for industrial applications.</div></div>","PeriodicalId":66,"journal":{"name":"Catalysis Science & Technology","volume":"15 2","pages":"Pages 344-354"},"PeriodicalIF":4.4,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142993924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mulatu Kassie Birhanu , Begüm Ünveroğlu Abdioglu , Ahmet Uçar
Excessive CO2 emissions from the traditional consumption of fossil fuels have led to severe environmental and ecological issues, including global temperature rise, atmospheric carbon imbalance, and expansion of desertification. To address these challenges, various green technologies and remediation techniques aimed at reducing CO2 emissions are being implemented worldwide. Among them, the electrochemical reduction (ECR) of CO2 into value-added fuels and chemicals has emerged as a promising strategy to complete the anthropogenic carbon cycle and promote sustainable development. However, the ECR of CO2 faces several challenges, including the inherent properties of CO2, harsh reduction conditions, poor catalytic performance, limited catalyst efficiency and stability, intermediate properties, competitive side reactions, and low product selectivity. Addressing these challenges requires a comprehensive understanding of both the extrinsic and intrinsic factors that influence the reduction process. This review provides a detailed examination of these factors, along with insights into the reduction principles and reaction mechanisms for the ECR of CO2. Extrinsic factors include the reduction temperature, electrolyte type and concentration, reaction cell design, catalyst/mass loading, electrolyte pH, pressure, and applied potential. Intrinsic factors encompass the active site properties of electrocatalysts, binding strength between CO2 and the reduction intermediates on the catalyst surface, electroactive surface area, nanocatalyst dimension, surface structure, morphology, and composition of the electrocatalyst. Additionally, we discuss advanced influences, such as electric fields, surface strain, dangling bonds, structural defects, ionomers, and hydrophobicity of electrocatalysts. The role and impact of each factor are analyzed, with a particular focus on the stability, reduction efficiency, and selectivity of the electrocatalyst and the product distribution in the ECR of CO2. This review aims to provide valuable insights for advancing the design and optimization of efficient and selective electrocatalysts to effectively address global CO2 emissions.
{"title":"Extrinsic and intrinsic factors for electrochemical reduction of carbon dioxide on heterogeneous metal electrocatalysts","authors":"Mulatu Kassie Birhanu , Begüm Ünveroğlu Abdioglu , Ahmet Uçar","doi":"10.1039/d4cy01091d","DOIUrl":"10.1039/d4cy01091d","url":null,"abstract":"<div><div>Excessive CO<sub>2</sub> emissions from the traditional consumption of fossil fuels have led to severe environmental and ecological issues, including global temperature rise, atmospheric carbon imbalance, and expansion of desertification. To address these challenges, various green technologies and remediation techniques aimed at reducing CO<sub>2</sub> emissions are being implemented worldwide. Among them, the electrochemical reduction (ECR) of CO<sub>2</sub> into value-added fuels and chemicals has emerged as a promising strategy to complete the anthropogenic carbon cycle and promote sustainable development. However, the ECR of CO<sub>2</sub> faces several challenges, including the inherent properties of CO<sub>2</sub>, harsh reduction conditions, poor catalytic performance, limited catalyst efficiency and stability, intermediate properties, competitive side reactions, and low product selectivity. Addressing these challenges requires a comprehensive understanding of both the extrinsic and intrinsic factors that influence the reduction process. This review provides a detailed examination of these factors, along with insights into the reduction principles and reaction mechanisms for the ECR of CO<sub>2</sub>. Extrinsic factors include the reduction temperature, electrolyte type and concentration, reaction cell design, catalyst/mass loading, electrolyte pH, pressure, and applied potential. Intrinsic factors encompass the active site properties of electrocatalysts, binding strength between CO<sub>2</sub> and the reduction intermediates on the catalyst surface, electroactive surface area, nanocatalyst dimension, surface structure, morphology, and composition of the electrocatalyst. Additionally, we discuss advanced influences, such as electric fields, surface strain, dangling bonds, structural defects, ionomers, and hydrophobicity of electrocatalysts. The role and impact of each factor are analyzed, with a particular focus on the stability, reduction efficiency, and selectivity of the electrocatalyst and the product distribution in the ECR of CO<sub>2</sub>. This review aims to provide valuable insights for advancing the design and optimization of efficient and selective electrocatalysts to effectively address global CO<sub>2</sub> emissions.</div></div>","PeriodicalId":66,"journal":{"name":"Catalysis Science & Technology","volume":"15 2","pages":"Pages 262-317"},"PeriodicalIF":4.4,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/cy/d4cy01091d?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142993971","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}
Viktor Söderholm , Marc Stajer , Carolin Savage , Leon Splittgerber , Dieter Vogt
Diphosphites like Biphephos are known for their combination of high activity and high linear selectivity in the Rh-catalyzed hydroformylation of terminal alkenes. However, like most phosphite-type ligands, Biphephos is prone to hydrolysis under acidic conditions and oxidation in the presence of oxygen, resulting in detrimental catalyst performance loss. In this work, we identified practical aspects that safeguard the long-term stability of Biphephos during the Rh-catalyzed hydroformylation of alkenes. Furthermore, different additives (amines and one epoxide) were explored as stabilizers for Biphephos. The Biphephos/Rh/stabilizer system was first extensively investigated via31P-NMR, followed by batch autoclave experiments (100 ml reactors), and finally applied in an upscaled reactor (300 ml) with an attached nanofiltration membrane unit for catalyst retention. With cyclohexene oxide (CHO) as a stabilizer for the ligand, stable operation with high catalyst retention (95%) was achieved for over 100 h at high product selectivity (l/b = 78).
{"title":"Towards continuous Rh-hydroformylation of long chain alkenes: handling methodology for the long-term stability of Biphephos in a continuous reactor with an attached membrane separation unit†","authors":"Viktor Söderholm , Marc Stajer , Carolin Savage , Leon Splittgerber , Dieter Vogt","doi":"10.1039/d4cy01148a","DOIUrl":"10.1039/d4cy01148a","url":null,"abstract":"<div><div>Diphosphites like Biphephos are known for their combination of high activity and high linear selectivity in the Rh-catalyzed hydroformylation of terminal alkenes. However, like most phosphite-type ligands, Biphephos is prone to hydrolysis under acidic conditions and oxidation in the presence of oxygen, resulting in detrimental catalyst performance loss. In this work, we identified practical aspects that safeguard the long-term stability of Biphephos during the Rh-catalyzed hydroformylation of alkenes. Furthermore, different additives (amines and one epoxide) were explored as stabilizers for Biphephos. The Biphephos/Rh/stabilizer system was first extensively investigated <em>via</em><sup>31</sup>P-NMR, followed by batch autoclave experiments (100 ml reactors), and finally applied in an upscaled reactor (300 ml) with an attached nanofiltration membrane unit for catalyst retention. With cyclohexene oxide (CHO) as a stabilizer for the ligand, stable operation with high catalyst retention (95%) was achieved for over 100 h at high product selectivity (l/b = 78).</div></div>","PeriodicalId":66,"journal":{"name":"Catalysis Science & Technology","volume":"15 2","pages":"Pages 592-604"},"PeriodicalIF":4.4,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/cy/d4cy01148a?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142994061","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}
Xin Zhang , Xinyu You , Yunfan Wang , Hexun Zhou , Xue Zhou , Abhishek Dutta Chowdhury
The methanol-to-aromatics (MTA) process, catalyzed by both unmodified and metal-loaded zeolite ZSM-5, offers a promising and sustainable approach for producing liquid aromatics directly from renewable feedstocks. However, traditional metal incorporation methods often result in metals being confined to the surface or pores of the zeolite. While this can enhance aromatic selectivity, it tends to negatively impact the catalyst's lifetime. To address this challenge, this study focuses on the impact of incorporating Zn into ZSM-5 using a post-synthetic hydrothermal substitution process, which differs from traditional metal impregnation methods. Our approach successfully integrates Zn directly into the zeolite framework, enhancing aromatic selectivity and extending catalyst lifetime—a counterintuitive result, as higher selectivity typically accelerates catalyst deactivation. We employed advanced characterization techniques, including operando UV-vis diffuse reflectance spectroscopy and solid-state NMR, to gain deeper insights into how the dual-cycle mechanism governs the MTA process. These findings will pave the way for developing upgraded zeolite-based catalytic systems for the valorization of C1 renewable feedstocks in aromatics production.
{"title":"The catalytic relevance of hydrothermally substituted Zn on the zeolite ZSM-5 during the methanol-to-aromatics process†","authors":"Xin Zhang , Xinyu You , Yunfan Wang , Hexun Zhou , Xue Zhou , Abhishek Dutta Chowdhury","doi":"10.1039/d4cy01168f","DOIUrl":"10.1039/d4cy01168f","url":null,"abstract":"<div><div>The methanol-to-aromatics (MTA) process, catalyzed by both unmodified and metal-loaded zeolite ZSM-5, offers a promising and sustainable approach for producing liquid aromatics directly from renewable feedstocks. However, traditional metal incorporation methods often result in metals being confined to the surface or pores of the zeolite. While this can enhance aromatic selectivity, it tends to negatively impact the catalyst's lifetime. To address this challenge, this study focuses on the impact of incorporating Zn into ZSM-5 using a post-synthetic hydrothermal substitution process, which differs from traditional metal impregnation methods. Our approach successfully integrates Zn directly into the zeolite framework, enhancing aromatic selectivity and extending catalyst lifetime—a counterintuitive result, as higher selectivity typically accelerates catalyst deactivation. We employed advanced characterization techniques, including <em>operando</em> UV-vis diffuse reflectance spectroscopy and solid-state NMR, to gain deeper insights into how the dual-cycle mechanism governs the MTA process. These findings will pave the way for developing upgraded zeolite-based catalytic systems for the valorization of C1 renewable feedstocks in aromatics production.</div></div>","PeriodicalId":66,"journal":{"name":"Catalysis Science & Technology","volume":"15 1","pages":"Pages 185-192"},"PeriodicalIF":4.4,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142912654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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