Effective Catalyst Research Articles

N,S‐Doped Ordered Mesoporous Carbon: An Effective Catalyst for the Formylation of Anilines and Stabilization of Pd Nanoparticles to Catalyze the Hydrogenation of Nitroarenes

AbstractN,S‐Doped highly ordered mesoporous carbon (N,S‐doped OMC) material was constructed by the nanocasting methodology using egg yolk with a high content of amino acids as a carbon precursor and SBA‐15 as a hard template, followed by carbonization at 500 °C under an N2 atmosphere, and then aqueous alkaline‐induced removal of the silica moiety of the SBA‐15 template. Prepared N,S‐doped OMC material efficiently catalyzed the formylation of various substituted anilines using DMF as a formylating agent in water, to afford N‐formylaniline derivatives in high to excellent yields. Also, as‐prepared N,S‐doped OMC was used to immobilize and stabilize the Pd nanoparticles in order to synthesize Pd@OMC material, which was used as an efficient catalyst for the hydrogenation of nitroaromatic compounds to the corresponding aniline derivatives. Nitroaromatic compounds are considered to be highly toxic water contaminant compounds, and their removal from wastewater by the hydrogenation is an interesting method. Furthermore, Pd@OMC catalyzed one‐pot tandem hydrogenation of nitrobenzene/formylation reactions was investigated, which gave corresponding N‐formyl aniline in high yield. Synthesized OMC and Pd@OMC were characterized using X‐ray diffraction (XRD), Brunauer‐Emmett‐Teller (BET), scanning electron microscopy (SEM), energy‐dispersive X‐ray spectroscopy (EDS), and transmission electron microscopy (TEM) analysis.

Efficient hydrogen production from formic acid dehydrogenation over ultrasmall PdIr nanoparticles on amine-functionalized yolk-shell mesoporous silica

Developing heterogeneous catalysts with exceptional catalytic activity over formic acid (HCOOH, FA) dehydrogenation is imperative to employ FA as an effective hydrogen (H2) carrier. In this work, ultrasmall (1.4 nm) and well-dispersed PdIr nanoparticles (NPs) immobilized on amine-functionalized yolk-shell mesoporous silica nanospheres (YSMSNs) with radially oriented mesoporous channels have been synthesized by a co-reduction strategy. The optimized catalyst Pd4Ir1/YSMSNs-NH2 (Pd/Ir molar ratio = 4:1) exhibited a remarkable turnover frequency (TOF) of 5818 h−1 and remarkable stability at 50 °C with the addition of sodium formate (SF), resulting in complete FA conversion and H2 selectivity, exceeding most of the solid heterogeneous catalysts in previous reports under similar circumstances. Kinetic isotope effect (KIE) exploration indicates the cleavage of the CH bond is regarded as the rate-determining step (RDS) during the FA dehydrogenation process. Such excellent catalytic properties arise from the ultrafine and well-dispersed PdIr NPs supported on the nanosphere support YSMSNs-NH2, the electronic synergistic effect of PdIr alloy NPs, and the strong metal-support interaction (MSI) effect between the introduced PdIr NPs and YSMSNs-NH2 support. This work offers a new paradigm for exploiting the highly effective silica-supported Pd-based heterogeneous catalysts over the dehydrogenation of FA.

Green Synthesis of Bimetallic Cu−Cd Nanoparticles and its Catalytic Activity in Pyrido [2,3‐d;6,5‐d] Dipyrimidine Derivatives

AbstractGreen synthesis nanoparticles have gained interest in recent years due to their environmental friendliness and sustainability. The current study focuses on the green synthesis of BMNP using spearmint leaves as a reducing and stabilizing agent. Because of their excellent catalytic characteristics, the synthesized bimetallic nanoparticles function as an effective catalyst in pyrido[2,3‐d:6,5‐d] pyrimidine derivatives. The synthesized nanoparticles are characterized using a variety of techniques, including FT‐IR analysis, SEM & EDX, XRD, and TEM. The FT‐IR study shows a reduction in functional groups in the leaf extract, confirming the metal nanoparticles’ stretching. SEM and EDX studies confirm the shape and elemental composition of bimetallic nanoparticles. XRD investigation showed that the synthesized NPs are crystalline, and the Scherrer equation was used to calculate the average crystallite size. The calculated size was 49 nm. TEM analysis confirms the core‐shell nature of BMNPs. The synthesized nanoparticles acted as a superior catalyst in pyrido[2,3‐d:6,5‐d] dipyrimidines derivatives. in the synthetic procedure, BMNPs enhanced the catalytic activity and reduced the reaction time with more yield, Compared to the previous study. and the synthesized compound [1–5] has been confirmed by FT‐IR, 1H‐NMR, and 13C‐NMR analysis. and it has given better results in in‐vivo anti‐diabetic activity by Streptozotocin nicotinamide. This induced model adult male albino Wistar derivatives show significant fasting blood glucose levels when compared to metformin hydrochloride. and its evaluated molecular docking study, exhibit excellent CDDOCKER energy.

Highly effective ruthenium catalyst support on La2Zr2O7 for ammonia decomposition to COx-free hydrogen

Pyrochlore-type La2Zr2O7 was prepared through a sol–gel route and served as a Ru-based catalyst support for ammonia decomposition to produce H2 without COx emission. The NH3 conversion over Ru/La2Zr2O7 could reach 69.5 % at 450 °C under the pure NH3 gas hourly space velocity (GHSV) of 30 000 mL.gcat-1h−1, which is approximately 3.1 times of that over Ru/ZrO2 and 2.2 times of Ru/La2O3 under the same conditions, respectively. It was found that the presence of oxygen vacancies on La2Zr2O7 surface can strongly interact with Ru particles to form the electronic strong metal-support interaction (EMSI), increasing the dispersion of Ru nanoparticles. Additionally, the mobile electrons are effectively transferred from La2Zr2O7 to the surface of Ru particles through the EMSI effect, consequently boosting the recombination desorption of N and ultimately contributing to the exceptional catalytic activity of Ru/La2Zr2O7.

Highly efficient Co-added Ni/CeO2 catalyst for co-production of hydrogen and carbon nanotubes by methane decomposition

The catalytic decomposition of methane (CDM) is a hydrogen and nanostructured carbon production process with minimal CO2 emission. Among the transition metal-based catalysts (e.g. Ni, Fe, Co, etc.), Ni-based catalysts are most widely studied due to the higher catalytic activity in decomposing methane. However, the limited lifespan of the catalyst makes it unsuitable for practical applications. Effective methane decomposition catalysts should be designed to optimize both reaction efficiency and catalyst lifetime. A Ni/CeO2 catalyst, developed in previous studies, Co was added to promote low-temperature (< 700 °C) activity manipulating the redox property of Co. Among the prepared catalysts with varying Ni:Co ratio, the methane conversion rate of the Ni8Co2/CeO2 catalyst was approximately twice that of the Ni10/CeO2 catalyst, confirming its excellent low-temperature activity. The reaction rate of Ni8Co2/CeO2 catalyst was 4.38 mmol/min∙gcat at 600 °C with WHSV of 36 L/gcat∙h. In terms of characteristics of carbon products, Raman spectroscopy analysis revealed that the carbon grown on the catalyst surface exhibited high crystallinity, with D-G band ratio (ID/IG) of 1.01. The fresh and used catalyst samples were characterized by TEM, XPS, XAS, and other methods to analyze the parameters affecting catalytic activity.

Statistical Design Approach for an Effective Catalyst in the Fenton Reaction in Case of Fe3O4-MOF MIL-88b (Fe) in Methylene Blue Degradation Kinetics

In this paper composites containing metal-organic framework MIL88b(Fe), nanoparticles magnetite (Fe3O4) or maghemite (γ-Fe2O3) modified by humic acids or ascorbic acid were synthesized and tested in the decomposition reaction of methylene blue. Analysis of predictive model based on multi-factor correlation analysis «physical-chemical properties — concentration of methylene blue after degradation» showed that in a line of selected parameters (initial iron concentration in sample, elemental cell parameter, Fe2+/Fe3+ ion ratio on sample surface, total iron ion released concentration, surface area specific, surface charge), a significant factor influencing Fenton reaction kinetics, is only the total concentration of the released iron ions (p-value = 0.0162). The influence of separate Fe2+ and Fe3+ ions and reaction time on the Fenton reaction kinetics was evaluated by multi-factor analysis. The results demonstrated that concentrations of released iron ions are statistically significant, with a square of the concentration of ions Fe2+ and the result of the reaction time to the concentration of ions Fe3+. A comparison of the sign and the coefficient values shows that an increase in ion concentration results in a reduction in methylene blue concentration, thereby accelerating the Fenton reaction rate, with Fe2+ ion concentration affecting more than Fe3+. The resulting model is proposed as a means of selecting a sample with the maximum Fenton reaction rate at a given point in time.

Core-shell Ru@Co2P synergistic catalyst as polysulfides adsorption-catalytic conversion mediator with enhanced redox kinetics in lithium-sulfur batteries

Lithium-sulfur batteries (LSBs) have emerged as the research hotspot due to their compelling merits, including high specific capacity (1675 mAh g−1), theoretical energy density (2600 Wh kg−1), environmental friendliness, and economic advantages. However, challenges still exist for further application due to their inherent issues such as the natural insulation, shuttle effect, and volume expansion of sulfur cathode during the continuous cycle processes. These factors obstruct the lithium ions (Li+) transfer process and sulfur utilization, resulting in significant impedance and inducing inferior battery performance. Herein, the core–shell nanocube anchoring ruthenium atoms and dicobalt phosphate (Ru@Co2P@NC) were fabricated as the effective catalyst and inhibited barrier for LSBs. On the one hand, the core–shell structure offers numerous channels to expedite Li+ diffusion. On the other hand, ruthenium (Ru) and dicobalt phosphate (Co2P) active sites facilitate the chemical capture of lithium polysulfides (LiPSs), accelerating sluggish kinetics. Ru@Co2P@NC modified cells not only exhibited a high initial specific capacity (1609.35 mAh g−1) at 0.5C and enduring stability with high specific capacity retention of 906.60 mAh g−1 at 0.5C after 400 cycles but also possessed low capacity attenuation rate of 0.07 % per cycle after 600 cycles (1C, Sulfur loading: 1.2 mg). Interestingly, the modified cells demonstrated a high specific capacity and long-cycle stability with high sulfur loading (from 1.984 to 3.137 mg), which provides a promising research approach for high-performance LSBs.

One-Pot Synthesis of Biochar from Industrial Alkali Lignin with Superior Pb(II) Immobilization Capability.

This study synthesized biochar through a one-pot pyrolysis process using IALG as the raw material. The physicochemical properties of the resulting biochar (IALG-BC) were characterized and compared with those of biochar derived from acid-treated lignin with the ash component removed (A-IALG-BC). This study further investigated the adsorption performances and mechanisms of these two lignin-based biochars for Pb(II). The results revealed that the high ash content in IALG, primarily composed of Na, acts as an effective catalyst during pyrolysis, reducing the activation energy and promoting the development of the pore structure in the resulting biochar (IALG-BC). Moreover, after pyrolysis, Na-related minerals transformed into particulate matter sized between 80 and 150 nm, which served as active adsorption sites for the efficient immobilization of Pb(II). Adsorption results demonstrated that IALG-BC exhibited a significantly superior adsorption performance for Pb(II) compared to that of A-IALG-BC. The theoretical maximum adsorption capacity of IALG-BC for Pb(II), derived from the Langmuir model, was determined to be 809.09 mg/g, approximately 40 times that of A-IALG-BC. Additionally, the adsorption equilibrium for Pb(II) with IALG-BC was reached within approximately 0.5 h, whereas A-IALG-BC required more than 2 h. These findings demonstrate that the presence of inorganic mineral components in IALG plays a crucial role in its resource utilization.

Insights into the dynamics of supported Au nanoparticles in the wet environments from first-principles and ReaxFF MD simulations

The interactions between metal and oxide supports have been widely studied, where the size effect of metal nanoparticles (NPs) and the gas environment play critical roles in catalytic performance. We employed density functional theory and ReaxFF reactive force field to investigate the size dependent properties of gold NPs supported on cerium dioxide, such as structural dynamics, adsorption, and electronic properties under wet environments. Distinct dynamic behaviors were observed in wet environments compared to vacuum conditions. In the wet environments, the hydroxide (OH) species preferentially adsorbs on the low coordination sites, such as edge sites, of NPs. This selective absorption induces a reconstruction effect on small NPs. Moderate-sized NPs exhibit significant surface reconstruction due to abundant OH adsorption at interface sites. However, this effect is negligible in larger NPs. A high interfacial population of OH significantly contributes the high catalytic performance of moderate-sized NPs. Moreover, OH adsorption modulates the charge distribution within the NPs, leading to their stabilization through OH-induced charge transfer. These findings provide insights into understanding and optimizing reactions in wet environments, offering a foundation for the development of more effective catalyst.

Green synthesis of Z-scheme N-doped g-C3N4/Nd-doped ZnO heterostructure by pomegranate waste peel with enhanced photocatalytic performance for organic pollutants removal and antibacterial activity

Nowadays, the growing global population and increased industrialization have exacerbated water pollution, posing a significant environmental threat. To tackle this issue, there is an urgent need for effective catalysts to remove pollutants. This study developed a novel N-doped g-C3N4/Nd-doped ZnO (NZ) heterostructure using a green approach by incorporating pomegranate peel waste as a stabilizing and capping agent. Characterization techniques confirmed successful NZ nanohybrid preparation. The synthesized NZ displayed high photocatalytic activity in degrading methylene blue (MB) and tetracycline (TC) pollutants found in wastewater, achieving degradation efficiencies of 95.3 % and 98.3 %, respectively. Meanwhile, it demonstrated satisfactory photostability after five-cycle experiments. The radical trapping experiments revealed that superoxide (O2−) and hydroxyl (OH) are the dominant active species and play an essential role in photocatalytic pollutant deterioration. Additionally, it exhibited suitable antimicrobial activity against Staphylococcus aureus and Vibrio cholerae bacterial strains. The enhanced performance is attributed to the abundant reaction sites of porous N-doped g-C3N4, the photo-redox capability of Nd-doped ZnO, and the efficient charge separation process in the Z-type heterojunction. This work advances sustainable and eco-friendly chemistry for the biosynthesis of organic/inorganic heterojunctions used in pollutant degradation and bacterial disinfection of wastewater.

Bulk CoCrFeNiAlMo high entropy alloy as high-efficient electrocatalyst in alkaline environment

Developing cost-efficient catalysts with high efficiency for water splitting has been considered as large challenge. Herein, the bulk high entropy alloys (HEAs) are fabricated through the vacuum induction melting, which could be beneficial to solving the above issues. At the same time, it also enhances the electrocatalysts activity and stability. The alloy composition is discovered to be crucial in the both hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) activity enhancements with the CoCrFeNiAlMo bulk HEA catalyst combination providing the exceptional catalytic activities. Forming the CoCrFeNiAlMo bulk HEA catalyst also significantly promotes the electrocatalytic cycling stabilities. Hence, the CoCrFeNiAlMo bulk HEA catalyst displays a small overpotential (261 mV @ 50 mA cm−2) and a corresponding Tafel slope (48.66 mV dec−1) for the OER in a 1.0 M KOH electrolyte. For HER, CoCrFeNiAlMo bulk HEA catalyst also possess a relatively small overpotential. Furthermore, it exhibits a relatively small cell voltage of 1.83 V at 50 mA cm−2 and superior durable for 14 h. This study presents a universal pathway for preparing sustainable high efficiency electrocatalysts, it demonstrates that the bulk HEAs have the potential to be effective catalysts in alkaline environments.

Experimental and computational investigations of supramolecular interactions in Cd(II)‐organic hydrate: catalytic applications in the Knoevenagel condensation reaction under solvent‐free conditions

A dinuclear cadmium(II) complex, [Cd2(Hhqc)2(H2O)4] (H3hqc= 4,8‐dihydroxyquinoline‐2‐carboxylic acid) was synthesized and characterized by single crystal X‐ray diffraction studies, elemental analyses and thermo‐gravimetric studies. The metal centers are found to be six coordinated with distorted pentagonal pyramidal geometry around them. The complex shows few significant intermolecular hydrogen bonding interactions to produce a three dimensional supramolecular network comprising of T8(2) water tapes. Besides these non‐covalent interactions few other supramolecular interactionsare also involved within the molecular dimer like π···π stacking, Cd···π etc. They have been analyzed using DFT calculations, MEP surface analyses and NCI plot index analyses. The detailed study‐highlights the complex interplay of π‐stacking, H‐bonding, and spodium interactions in stabilizing the dimers of complex, which providing precious insights into their energetic and structural characteristics. Furthermore, the catalytic efficiency of the synthesized complex has been investigated as an effective heterogeneous catalyst in the Knoevenagel condensation reaction under solvent‐free conditions.

LaCuMnOx perovskite activating persulfate for the degradation of bisphenol A: excellent tolerance to hypersaline environment

AbstractBackgroundLaCuMnOx (LCMO) perovskite was designed as an effective catalyst to activate peroxydisulfate (PDS) to remove bisphenol A (BPA) in hypersaline wastewater.ResultsIn the LCMO/PDS system, BPA (10 mg/L) was removed completely and the mineralization degree reached 74.9% in the presence of 0.12 g/L catalyst and 1.2 mM PDS. The BPA removal efficiency was still almost 100% even after five cycles. Metal ion leakage also indicated the stability of the catalytic system. •OH, SO4•−, 1O2, and O2•− all contributed to BPA removal, and O2•− accounted for the greatest contribution. The presence of oxygen vacancies (Vo··) on the surface of the catalyst was important for PDS activation and the formation of active species. In addition, the system could still maintain outstanding performance even when [Cl−] and [SO42−] were 100 g/L. CO32− and HCO3− inhibited BPA degradation greatly, even at very low concentrations. The inhibitory effect was related to changes in the pH of the solution caused by the addition of CO32− and HCO3−. This effect could be eliminated by adjusting the pH.ConclusionThe system showed excellent catalytic performance, stability, and inorganic anion tolerance, indicating its potential for application in hypersaline wastewater treatment. © 2024 Society of Chemical Industry (SCI).

Asymmetric Transfer Hydrogenation of Ketones Improved by PNN-Manganese Complexes.

Chiral manganese(I) complexes that contain carbocyclic-fused 8-amino-5,6,7,8-tetrahydroquinolinyl groups that are appended with distinct para-R substituents have proven to be effective catalysts in the asymmetric transfer hydrogenation (ATH) of a wide range of ketones (48 examples). Notably, Mn2 proved to be the most productive catalyst, allowing an outstanding turnover number of 8300 with catalyst loadings as low as 0.01 mol %. Furthermore, this catalytic protocol shows considerable promise for applications in the synthesis of chiral drugs such as Lusutrombopag.

Atomically dispersed ruthenium in transition metal double layered hydroxide as a bifunctional catalyst for overall water splitting

Efficient and sustainable energy conversion depends on the rational design of single-atom catalysts. The control of the active sites at the atomic level is vital for electrocatalytic materials in alkaline and acidic electrolytes. Moreover, fabrication of effective catalysts with a well-defined surface structure results in an in-depth understanding of the catalytic mechanism. Herein, a single atom ruthenium dispersed in nickel-cobalt layered hydroxide (Ru-NiCo LDH) is reported. Through the precise controlling of the atomic dispersion and local coordination environment, Ru-NiCo LDH//Ru-NiCo LDH provides an ultra-low overpotential of 1.45 mV at 10 mA cm−2 for the overall water splitting, which surpasses that of the state-of-the-art Pt/C/RuO2 redox couple. Density functional theory calculations show that Ru-NiCo LDH optimizes hydrogen evolution intermediate adsorption energies and promotes O-O coupling at a Ru-O active site for oxygen evolution, while Ni serves as the water dissociation site for effective water splitting. As a potential model, Ru-NiCo LDH shows enhanced water splitting performance with potential for the development of promising water-alkaline catalysts.

C60 Fullerene-Induced Reduction of Metal Ions: Synthesis of C60-Metal Cluster Heterostructures with High Electrocatalytic Hydrogen-Evolution Performance.

Metal clusters, due to their small dimensions, contain a high proportion of surface atoms, thus possessing a significantly improved catalytic activity compared with their bulk counterparts and nanoparticles. Defective and modified carbon supports are effective in stabilizing metal clusters, however, the synthesis of isolated metal clusters still requires multiple steps and harsh conditions. Herein, we develop a C60 fullerene-driven spontaneous metal deposition process, where C60 serves as both a reductant and an anchor, to achieve uniform metal (Rh, Ir, Pt, Pd, Au and Ru) clusters without the need for any defects or functional groups on C60. Density functional theory calculations reveal that C60 possesses multiple strong metal adsorption sites, which favors stable and uniform deposition of metal atoms. In addition, owing to the electron-withdrawing properties of C60, the electronic structures of metal clusters are effectively regulated, not only optimizing the adsorption behavior of reaction intermediates but also accelerating the kinetics of hydrogen evolution reaction. The synthesized Ru/C60-300 exhibits remarkable performance for hydrogen evolution in an alkaline condition. This study demonstrates a facile and efficient method for synthesizing effective fullerene-supported metal cluster catalysts without any pretreatment and additional reducing agent.

Oxygen vacancies-rich CoMoO4 nanosheets facilitate the electroreduction of nitrite to ammonia

Electrocatalytic reduction is a promising method to remove NO2−; not only can it deal with environmental issues, but it can also recycle NO2− to form NH3. This study involved the preparation of oxygen vacancies-rich monoclinic cobalt molybdate nanosheets on nickel foam (CoMoO4/NF) employing a hybrid approach of hydrothermal and calcination reduction techniques renders highly effective catalysts for electroreduction of nitrite (NO2−RR). The presence of oxygen vacancies increases carrier density, enhancing electrical conductivity, reducing resistance, and accelerating electron transfer. Additionally, it serves as an active site for absorbing NO2−. In an aqueous solution containing 0.5 M Na2SO4 and 0.1 M NO2−, the Faraday efficiency (FE) of CoMoO4/NF reaches an impressive 98.6 ± 0.02 % at −0.8 V vs. RHE, and NH3 yield demonstrates a commendable performance, attaining 32.72 ± 0.17 mg h−1 cm−2. Meanwhile, it exhibits robust and enduring characteristics throughout the stability tests. Employing CoMoO4/NF as the cathode, the Zn−NO2− battery demonstrates a peak power density of 5.94 mW cm−2 alongside an NH3 yield of 3.88 mg h−1 cm−2 and an FE of 91.88 %. Furthermore, density functional theory calculations uncover the significant influence of oxygen vacancies on enhancing nitrite adsorption and activation over the CoMoO4 surface and bring to light possible reaction pathways.

Silicon Clathrate-Supported Catalysts with Low Work Functions for Ammonia Synthesis.

Diamond-type silicon has a work function of ≈4.8eV, and conventional n- or p-type doping modifies the value only between 4.6 and 5.05eV. Here, it is shown that the alkali clathrates AxSi46 have substantially lower work functions approaching 2.6eV, with clear trends between alkali electropositivity and clathrate cage size. The low work function enables alkali clathrates such as K8Si46 to be effective Haber-Bosch catalyst supports for NH3 synthesis. The catalytic properties of Si, Ge, and Sn-based clathrates are investigated while supporting Fe and Ru on the surface. The activity largely scales with the work function, and low activation energies below 60kJ mol-1 are observed due to strong electron donation effects from the support. Ru metal and Sn clathrates seem to be unsuitable for stability issues. Compared to other similar hydride/electride catalysts, the simple structure and composition combined with stability in air/water make a systematic study of these clathrates possible and open the door to other electron-rich Zintl phases and related intermetallics as low-work function materials suitable for catalysis. The observed low work function may also have implications for other existing electronic applications.

Promoting C-Cl Bond Activation via a Preoccupied Anchoring Strategy on Vanadia-Based Catalysts for Multi-Pollutant Control of NOx and Chlorinated Aromatics.

Regulating vanadia-based oxides has been widely utilized for fabricating effective difunctional catalysts for the simultaneous elimination of NOx and chlorobenzene (CB). However, the notorious accumulation of polychlorinated species and excessively strong NH3 adsorption on the catalysts lead to the deterioration of multipollutant control (MPC) activity. Herein, protonated sulfate (-HSO4) supported on vanadium-titanium catalysts via a preoccupied anchoring strategy are designed to prevent polychlorinated species and alleviate NH3 adsorption for the multipollutant control. The obtained catalysts with -HSO4 modification achieve an excellent NOx and CB conversion with turnover frequency values of ∼ 3.63 and 17.7 times higher than those of the pristine, respectively. The protonated sulfate promotes the formation of polymeric vanadyl with a higher chemical state and d-band center of V. The modulated catalysts not only substantially alleviate the competitive adsorption of multipollutant via the "V 3d-O 2p-S 3p" network, but also distinctly strengthen the Brønsted acid sites. Besides, the introduced proton donor of the -HSO4 connecting polymeric structure could markedly reduce the reaction barrier of breaking the C-Cl bond. This work paves an advanced way for low-loading vanadium SCR catalysts to achieve highly efficient NOx and CB oxidation at a low temperature.

Bimetallic Fe, Co-Modified TiO2 Derived from NH2-MIL-125(Ti) as an Efficient Photocatalyst for N2 Fixation

The conversion of nitrogen (N2) and water (H2O) into NH3 by photocatalysis under ambient conditions has been considered an environmentally friendly strategy. However, developing effective catalysts for N2 fixation is still challenging. Herein, we report a bimetallic JH Fe, Co/TiO2 derived from NH2-MIL-125(Ti) by the fast Joule heating (FJH) method for visible–light–driven catalytic N2 fixation. It was found that the photocatalytic N2 reduction efficiency of bimetallic FC@TiO2-JH was improved, enabling an NH3 yield rate of 110.14 µmol g−1 h−1 without any sacrificial agents. Furthermore, the rate was higher than those of Fe@TiO2-JH and Co@TiO2-JH, suggesting that the synergistic effect between Fe and Co broke the electronic equilibrium and increased the center of its d-band, enhancing electronic feedback to the antibonding π* orbitals of N2 while weakening the bonding energy of N≡N. Meanwhile, the rate was about 2.75 times higher than that of FC@TiO2-TF, which was calcined in a tube furnace. It is assumed that FJH might lead to the formation of lattice defects, leading to localized charge deficiency, enhanced carrier separation, and transport. Thus, doping of Fe and Co synergistically interacted with the defects produced from FJH, facilitating the photocatalytic reduction process. As detected, it had a greater ability to separate hole–electron pairs and transferred electrons to adsorbed N2 at faster rates. Our work demonstrates a prospective strategy for designing bimetallic catalysts derived from NH2-MIL-125(Ti) for N2 fixation.