Fe Loading Research Articles

Two‐Dimensional Organometallic Frameworks with Pyridinic Single‐Metal‐Atom Sites for Bifunctional ORR/OER

AbstractAchieving efficient bifunctional oxygen reduction and evolution reactions (ORR/OER) on non‐noble metal catalysts is desirable but remains a significant challenge. Herein, inspired by the experimentally synthesized (phen2N2)FeCl molecule, a stable 2D organometallic framework, namely (phen2N2)FeCl monolayer, is proposed as a qualified candidate by means of constant‐potential first‐principles computations. Unlike most 2D organometallic frameworks that feature pyrrolic coordination, the (phen2N2)FeCl monolayer exhibits a pyridinic‐type FeN4 ligation environment. The unique structure of the monolayer enables a high single‐atom Fe loading in a heterogeneous system, superior to the typical FeNC materials. Constant‐potential energy analysis and microkinetic modeling demonstrate that the monolayer holds great potential for facilitating bifunctional ORR/OER in both the acidic and alkaline conditions, showing theoretical activity higher than the FeNC materials, (phen2N2)FeCl molecule, and Pt/IrO2. Moreover, (phen2N2)MCl monolayers (M = Mn, Co, and Ni) are explored, and the (phen2N2)MnCl monolayer is also identified to have excellent bifunctional activity. This study highlights the rational design of local coordination environments for boosting the electrocatalytic performance of 2D organometallic frameworks.

Performance evaluation of Fe-loaded regenerated activated carbon prepared from waste mercuric chloride catalysts

In this paper, the waste mercuric chloride catalysts (WMCC) were successfully recycled and then modified by ferrum (Fe) loading. Various analysis techniques were used to study the reaction mechanism of Fe loading modified regenerated activated carbon (RAC). Results show that the absorbed organic matter is the main reason causing the WMCC inactivation and it will thoroughly decompose beyond 334 °C. With assistance of microwave energy, the WMCC can be activated by roasting at 500 °C for 30 min. At this moment, the base material of the RAC still maintained the graphite structure. The experimental results of the adsorption performance of Fe-loaded RAC that prepared from different Fe loading additions on arsenic (As) in arsenic-containing wastewater show that: the Fe-loaded RAC with Fe loading addition of 12.51 wt% has a maximum As (V) removal efficiency of 86.76%. The main phase composition of the Fe-loaded RAC is Fe2O3 and Fe3O4, and its defect density is the largest, which is considered to be the main reason for the effective adsorption of As (V).

Novel iron sand-derived α-Fe2O3/CaO2 bifunctional catalyst for waste cooking oil-based biodiesel production.

The main aim of this work was to develop a heterogeneous Fe2O3/CaO2 bifunctional catalyst prepared from iron sand and 3 different CaO2 sources (CaCO3, Ca (OH)2, and limestone) using wet impregnation and calcination methods for biodiesel production. The effects of different CaO2 sources and Fe/Ca ratio in the catalyst were investigated to provide insight into the catalyst character and biodiesel yield. X-ray diffraction, X-ray fluorescence, and scanning electron microscopy analyses were used to characterize the catalyst. CaCO3 was concluded as the best CaO2 source, while the best Fe/Ca configuration was found to be 1:4, giving the highest biodiesel yield (97.0401%) with no diglycerides. Greater addition of Fe loading would result in an amorphous structure, and all catalysts were relatively crystalline. Fe was concluded to favor the esterification reaction and biodiesel formation, while CaO2 was seen to favor the transesterification reaction and fatty acid methyl ester (FAME) formation. The catalyst mechanism was also established in this study, where esterification of free fatty acid (FFA) and glycerol took place on the acid site to produce diglyceride and transesterification of triglyceride by methanol occurred on the basic site.

Function of Fe(III) in naphthalene adsorption on typical clay minerals and humic acid complexes

The adsorption of naphthalene on montmorillonite (Mon)–humic acid (HA) and chlorite (Chl)–HA complexes often occurs in environments with high concentrations of Fe(III) loading. But the functions of Fe(III) in naphthalene adsorption on Mon-HA and Chl-HA complexes are unclear. In this study, mineral–organic complexes of HA and the common minerals Mon and Chl were prepared for studying the mechanisms and characteristics of naphthalene adsorption on Mon, Chl and HA complexes in the presence of Fe(III). The results showed thatfor Mon–Fe–HA, as organic matter contents (foc)increased from 2.77% to 14.63%, Kd increased from 0.29 to 0.80 L·g−1. This indicated that the adsorption capacity of Mon–Fe–HA for naphthalene increased as foc increased in the presence of Fe(III). However, at foc≤ 5.41%, the adsorption capacity of Mon–Fe–HA for naphthalene was less than that of Mon–HA; at foc>5.41%, the adsorption capacity of Mon–Fe–HA for naphthalene exceeded that of Mon–HA. This suggested that Fe(III) inhibited the adsorption of naphthalene on Mon–Fe–HA at foc≤ 5.41%, and promoted the adsorption at foc>5.41%. For Chl–Fe–HA, as foc increased from 2.77% to 14.63%, Kd increased from 0.33 to 1.21 L·g−1; the Kd for naphthalene adsorption on Chl–Fe–HA exceeded that for Chl–HA regardless of foc, indicating that Fe(III) always promoted the adsorption of naphthalene on Chl–Fe–HA regardless of foc. And Fe(III) had different effects on the adsorption of naphthalene on Mon–Fe–HA and Chl–Fe–HA, which is due to the differences in the structure, pore structure and functional groups of Mon and Chl. These findings provide a basis for accurately assessing the adsorption of such pollutants on mineral–organic complexes with minerals.

Photo-oxidative extractive desulfurization of dibenzothiofene over Fe2O3-CeO2 nanocomposites at visible light irradiation

This research represents the role of Fe2O3 loading (10–100%) to ceria on the simultaneous oxidative and extractive photo-desulfurization of dibenzothiophene (DBT) in the visible light range. The catalysts were characterized by several known analyses in photocatalysis. The results revealed the FexCeO1-xOy solid solution fabrication with Fe loading up to 20%. While, Fe2O3 segregation was indicated at the higher loading percent. The Fe15Ce85 catalyst exhibited the highest photocatalytic DBT removal of 94.4%. The optimum conditions of 0.15 g catalyst, 2:1 solvent/oil and 2:1 H2O2/S for 2 h were obtained. The Fe15Ce85 higher activity was attributed to the influenced textural and chemical properties induced by Fe/Ce solid solution fabrication. Also, the small band gap and red shift in visible light absorption assigned to the Fe-Ce nanocomposite are reasons for high activity. The desulfurization mechanism was also proposed.

Surface modulated Fe doping of β‐Ni(OH)2 nanosheets for highly promoted oxygen evolution electrocatalysis

AbstractActive yet low‐cost electrocatalysts for water oxidation are crucial for the development of hydrogen energy economy. The Fe doping into Ni(OH)2 dramatically enhances catalytic activity toward oxygen evolution reaction (OER) but fabricating Ni(OH)2 of high Fe loading is still challenging. Herein, we report a one‐pot strategy to prepare disordered β‐Ni(OH)2 nanosheets with a high Fe doping level (9.9 at%, D‐Fe‐Ni(OH)2). By engaging 1,4‐phenylenediphosphonic acid (BDPA), FexBDPAy precursors are in situ generated in a growth solution containing Fe3+ ions, which decrease the reaction kinetics of Ni2+ and Fe3+ ions at the surface of Ni foam. This prevents the deconstructive hydrolysis by Fe3+ ions and enables a high Fe‐doping in D‐Fe‐Ni(OH)2. The as‐prepared D‐Fe‐Ni(OH)2 affords 10 mA cm−2 at an ultralow OER overpotential of 194 mV in alkaline media. This work offers a promising strategy of engaging organic ligands to achieve high‐doping levels for the construction of efficient electrocatalysts.image

Physicochemical Features and NH3-SCR Catalytic Performance of Natural Zeolite Modified with Iron—The Effect of Fe Loading

In modern dual-pressure nitric acid plants, the tail gas temperature usually exceeds 300 °C. The NH3-SCR catalyst used in this temperature range must be resistant to thermal deactivation, so commercial vanadium-based systems, such as V2O5-WO3 (MoO3)-TiO2, are most commonly used. However, selectivity of this material significantly decreases above 350 °C due to the increase in the rate of side reactions, such as oxidation of ammonia to NO and formation of N2O. Moreover, vanadium compounds are toxic for the environment. Thus, management of the used catalyst is complicated. One of the alternatives to commercial V2O5-TiO2 catalysts are natural zeolites. These materials are abundant in the environment and are thus relatively cheap and easily accessible. Therefore, the aim of the study was to design a novel iron-modified zeolite catalyst for the reduction of NOx emission from dual-pressure nitric acid plants via NH3-SCR. The aim of the study was to determine the influence of iron loading in the natural zeolite-supported catalyst on its catalytic performance in NOx conversion. The investigated support was firstly formed into pellets and then impregnated with various contents of Fe precursor. Physicochemical characteristics of the catalyst were determined by XRF, XRD, low-temperature N2 sorption, FT-IR, and UV–Vis. The catalytic performance of the catalyst formed into pellets was tested on a laboratory scale within the range of 250–450 °C using tail gases from a pilot nitric acid plant. The results of this study indicated that the presence of various iron species, including natural isolated Fe3+ and the introduced FexOy oligomers, contributed to efficient NOx reduction, especially in the high-temperature range, where the NOx conversion rate exceeded 90%.

Microwave-assisted decomposition of waste plastic over Fe/FeAl2O4 to produce hydrogen and carbon nanotubes

This study experimentally investigated a novel approach for producing hydrogen and carbon nanotubes (CNTs) via high-density polyethylene (HDPE) cracking using Fe/FeAl2O4 under microwave radiation. We tested catalyst performance at different Fe-FeAl2O4 ratios and under different microwave powers and characterized. The catalysts were characterized by XRD, SEM/EDS, TEM, Raman, and TGA techniques. Additionally, we investigated the relationship between the structural properties of the catalysts and their activities. The results showed that Fe/FeAl2O4 catalyst can efficiently crack plastics into hydrogen and CNTs with the assistance of microwaves, and the catalyst with 30 wt% Fe loading exhibited optimal microwave absorption and catalytic activity. The hydrogen production is 47.03 mmol/gplastic (84.96 vol%). Furthermore, we evaluated the effect of microwaves on catalysts by simulating the electromagnetic field distribution, finding that the material was heated in the form of eddy current loss. CNTs follow different growth mechanisms on Fe and FeAl2O4 in the catalyst, namely the tip growth mechanism and the base growth mechanism, respectively.

Molecular Bridging Enables Isolated Iron Atoms on Stereoassembled Carbon Framework To Boost Oxygen Reduction for Zinc-Air Batteries.

Realizing the synergy between active site regulation and rational structural engineering is essential in the electrocatalysis community but still challenging. Here, a matrix-confined co-pyrolysis strategy based on molecular bridging is demonstrated to realize highly dispersed Fe atoms on stereoassembled carbon framework. Both polyacrylonitrile matrix and organic linker from metal-organic frameworks (MOFs) provide sufficient N-anchoring sites for the generation of Fe-N4 moieties. A high Fe loading of 2.9 wt.% is readily achieved based on the scalable approach without post-treatment. Owing to the presence of highly exposed Fe-N-C sites and well-tuned pore structures, isolated Fe atoms on porous carbon nanofiber framework (Fe-SA/NCF) exhibits decent oxygen reduction activity and stability in alkaline conditions via a near four-electron path, demonstrating superior performance as air cathode for zinc-air batteries (ZABs) to commercial Pt/C catalyst.

Degradation of methylene blue-ciprofloxacin and hydrogen production simultaneously using combination of electrocoagulation and photocatalytic process with Fe-TiNTAs

The study reported in this paper combines the electrocoagulation and photocatalysis for the simultaneous degradation of methylene blue dyes (MB)-antibiotic ciprofloxacin (CP) and production of hydrogen. The pollutant removal process was conducted by combining adsorption by electrocoagulation and degradation by photocatalysis. Meanwhile, H2 was produced by reducing the H+ on the cathode and the photocatalyst surface in a reactor made of acrylic equipped with aluminum as the anode, stainless steel 316 plates as a cathode, Fe-doped titania nanotube arrays (TiNTAs) as a photocatalyst, and a 250-W mercury lamp as the light source. TiNTAs were synthesized via anodization and followed by the successive ionic layer adsorption and reaction (SILAR) method to incorporate Fe as the dopant. In particular, the effects of Fe loading in the composite photocatalyst are investigated. XRD results showed that TiO2 nanotubes arrays comprise a 100% anatase phase. FESEM, EDX, TEM, and HRTEM analysis confirmed the formation of the nanotubular structure of TiO2 and the presence of Fe deposited on the surface. The UV–Vis DRS indicated that the bandgap of Fe-TiNTAs reduced with Fe introduction, as compared to that of the undoped TiNTAs. The results showed that accumulation of the produced hydrogen from the combination of electrocoagulation-photocatalytic system is greater than that which is obtained using individual electrocoagulation or photocatalytic system. The combined process exhibited an enhanced degradation ability of methylene blue and ciprofloxacin, as well as in the H2 production.

Identifying Monomeric Fe Species for Efficient Direct Methane Oxidation to C1 Oxygenates with H2O2 over Fe/MOR Catalysts

Exploring advanced catalysts and reaction systems operated at mild reaction conditions is crucial for conducting the direct methane oxidation reaction toward oxygenate products. Many efforts have been put into research on pentasil−type (MFI) zeolites based on mononuclear and/or binuclear iron sites, using H2O2 as the oxidant. In this work, we present a modified liquid ion−exchange method to better control Fe loading in a mordenite−type (MOR) zeolite with a Si/Al molar ratio of 9. The optimized Fe/MOR catalyst showed excellent performance in the direct methane oxidation reaction with turnover frequencies (TOFs) of 555 h−1 to C1 oxygenates, significantly better than the reported activity. Multiple comparative experiments were conducted to reveal the mechanism behind the performance. Strikingly, the active sites in the Fe/MOR catalyst were found to be mononuclear iron sites, confirmed by transmission electron microscopy (TEM), ultraviolet−visible diffuse reflectance spectroscopy (UV−vis DRS), and X-ray absorption spectroscopy (XAS). Increasing the iron loading led to the aggregation of the iron sites, which tend to trigger undesirable side reactions (i.e., H2O2 decomposition and over−oxidation), resulting in a significant decrease in TOFs to C1 oxygenates.

High loading of single atomic iron sites in Fe–NC oxygen reduction catalysts for proton exchange membrane fuel cells

Non-precious iron-based catalysts (Fe–NCs) require high active site density to meet the performance targets as cathode catalysts in proton exchange membrane fuel cells. Site density is generally limited to that achieved at a 1–3 wt%(Fe) loading due to the undesired formation of iron-containing nanoparticles at higher loadings. Here we show that by preforming a carbon–nitrogen matrix using a sacrificial metal (Zn) in the initial synthesis step and then exchanging iron into this preformed matrix we achieve 7 wt% iron coordinated solely as single-atom Fe–N4 sites, as identified by 57Fe cryogenic Mössbauer spectroscopy and X-ray absorption spectroscopy. Site density values measured by in situ nitrite stripping and ex situ CO chemisorption methods are 4.7 × 1019 and 7.8 × 1019 sites g−1, with a turnover frequency of 5.4 electrons sites−1 s−1 at 0.80 V in a 0.5 M H2SO4 electrolyte. The catalyst delivers an excellent proton exchange membrane fuel cell performance with current densities of 41.3 mA cm−2 at 0.90 ViR-free using H2–O2 and 145 mA cm−2 at 0.80 V (199 mA cm−2 at 0.80 ViR-free) using H2–air.

Liquid-Phase Selective Hydrogenation of Furfural to Furfuryl Alcohol over Ferromagnetic Element (Fe, Co, Ni, Nd)-Promoted Pt Catalysts Supported on Activated Carbon

Ferromagnetic element (x = Fe, Co, Ni, and Nd)-promoted Pt/AC catalysts were prepared by co-impregnation method or physical mixing and tested in the liquid-phase hydrogenation of furfural to furfuryl alcohol (FA) under mild conditions (50 °C and 20 bar H2) using water and methanol as the solvent. Among the various catalysts studied, the 0.15FePt/AC exhibited complete conversion of furfural with an FA selectivity of 74% after only 1 h of reaction time in water. The promotional effect of the bimetallic catalysts became less pronounced when methanol was used as the solvent and a 2-furaldehyde dimethyl acetal solvent product was formed. The superior catalyst performances were correlated with the higher Pt dispersion, the presence of low coordination Pt sites, and the strong Pt–Fe interaction as characterized by X-ray diffraction, H2 temperature-programmed reduction (H2-TPR), N2 physisorption, and infrared spectroscopy of the adsorbed CO (CO-IR). However, to simply use a magnet for catalyst separation, 0.5 wt% Fe was the minimum Fe loading on the Pt/AC. The 0.5FePt/AC still exhibited good magnetic properties after the third consecutive runs.

Cu‐Fe/activated carbon catalyst for low‐temperature CO‐selective catalytic: Modification and denitration mechanism

AbstractTo study the Cu‐Fe modification and CO denitration mechanism of carbon‐based sorbent, coconut‐husk activated carbon (AC), which was activated via air thermo‐oxidation and modified using Cu(NO3)2 and Fe(NO3)2 was examined. In addition, the denitration activity was evaluated. The effects of air thermo‐oxidative activation, as well as Cu(NO3)2 and Fe(NO3)2 immersion on the pore texture and surface characteristics of the carbon materials, were examined by scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET) analysis, X‐ray powder diffraction (XRD) and Fourier‐transform infrared (FTIR) spectroscopy. The reduction performance and CO adsorptive property of xCu‐yFe/AC catalyst was measured using hydrogen temperature‐programmed reduction (H2‐TPR) and carbon monoxide temperature‐programmed desorption (CO‐TPD). The xCu‐yFe/AC's denitration activity showed that physical adsorption is a priority, then chemical adsorption recovers the denitration activity after physical adsorption saturation. The modification mechanism showed that higher loading of Cu and Fe resulted in enhanced dispersivity and more active sites but decreased specific surface area and pore volume. Then, the capability of physical adsorption decreased. Moreover, higher Fe loading was conducive to improved dispersivity of copper oxide species. The effects of Cu and Fe modification on the majority of functional groups were insignificant. The reduction peak at approximately 150°C indicated that the xCu‐yFe/AC catalyst has strong reduction characteristics. The number of CO active adsorption sites increased by high loading quantity at high‐temperature. The CO‐selective catalytic reduction (SCR) denitration conforms to Langmuir–Hinshelwood mechanism. The reciprocal transformation between Fe2+ and Fe3+, Cu+ and Cu2+, which is conducive to the rapid progress of the CO‐SCR reaction.

Preparation of supported Fe2O3‐Cl/β‐zeolite catalyst and its application in the selective oligomerization reaction of isobutene in mixed C4

AbstractBACKGROUNDIsobutene oligomerization is a very promising reaction, and it has always been a research hotspot in the separation of mixed C4. A supported catalyst is a promising olefin oligomerization catalyst. In the work reported, a supported Fe2O3‐Cl/β‐zeolite molecular sieve catalyst was synthesized by changing the loading amount of various active components, and its catalytic effect on the selective oligomerization of isobutene was studied. The catalyst was characterized using various techniques. The experiments were carried out in a fixed bed reactor, and the effects of Fe loading, temperature and reaction space airspeed were studied.RESULTSThe catalyst has a good catalytic effect on this reaction with the load at 3%, the temperature at 70 °C, the pressure at 1 MPa and the reaction airspeed at 2 h−1.CONCLUSIONSThe conversion of isobutene was above 90%, the selectivity of C8 was around 80% and the loss of n‐butene was very small. © 2022 Society of Chemical Industry (SCI).

Insight into the Sb(III) and Sb(V) removal mechanisms on porous Fe-Ti-chitosan composite: Experiment and DFT calculations

Currently, increasing attention has been concentrated on antimony (Sb) pollution and its ecological damage in ecosystems, where efficient and green treatment technologies, particularly for aquatic Sb(III) and Sb(V), are urgently necessary. Herein, a novel Fe-Ti-chitosan (FTC) composite was prepared via a facile coprecipitation method for aquatic Sb(III) and Sb(V) elimination. A 2/1 mol ratio of Fe/Ti (FTC-2/1) was evaluated as the suitable proportion with the highest adsorption performance for Sb(III) and Sb(V). Detailed morphological analysis indicated that chitosan could not only act as the porous framework for Fe and Ti loading but also effectively inhibit the particle aggregation, in which the BET surface area of FTC-2/1 reached 235.23 m2·g−1. The unique three-dimension porous framework endowed the material with abundant surface hydroxyl groups and further promoted the diffusion kinetics of Sb(III) and Sb(V) in the porous structure. According to the density functional theory (DFT) calculations, the highest adsorption efficiency of FTC-2/1 was rationally interpreted by the preferential adsorption of the Fe-Ti bidentate complex towards Sb(III) and Sb(V), which was attributed to the redistribution of the interfacial electron induced by the Fe-O-Ti linkage. The driving force of the highest adsorption energy was derived from the electronic structure reconstruction of adsorbed antimony molecules and Fe-Ti atoms, in which a stable pd orbital hybridization occurred between O 2p and Fe/Ti 3d. This work demonstrated that FTC-2/1 is promising and environmentally friendly adsorbent for antimony elimination, and may provide a potent perspective for the interfacial analysis of binary oxides.

Sediment Records Shed Light on Drivers of Decadal Iron Concentration Increase in a Boreal Lake

AbstractIncreasing iron (Fe) concentrations are found in lakes on a wide geographical scale but exact causes are still debated. The observed trends might result from increased Fe loading from the terrestrial catchment, but also from changes in how Fe distributes between the water column and the sediments. To get a better understanding of the causes we investigated whether there has been any change in the sediment formation of Fe sulfides (FeS) as an Fe sink in response to declining atmospheric sulfur (S) deposition during recent decades. For our study, we chose Lake Bolmen in southern Sweden, a lake for which we confirmed that Fe concentrations in the water column have strongly increased along with water color during 1966–2018. Our investigations showed that Fe accumulation and speciation varied independently of S accumulation patterns in the Lake Bolmen sediment record. Thus, we were not able to relate the positive trend in Fe concentrations to reduced FeS binding in the sediments. Furthermore, we found that Fe accumulation rates increased along with lake water Fe concentrations, indicating that increased catchment loading rather than a change in the distribution between the sediments and the water column has driven the increase in Fe concentrations. The increased loading may be due to land‐use change in the form of an extensive expansion of coniferous forest during the past century. Altered forest management practices and increased precipitation may have led to enhanced weathering and erosion of organic soil layers under aging coniferous forest.

Fe Nanoparticle Size Control of the Fe-MOF-Derived Catalyst Using a Solvothermal Method: Effect on FTS Activity and Olefin Production.

The design of a highly active Fe-supported catalyst with the optimum particle and pore size, dispersion, loading, and stability is essential for obtaining the desired product selectivity. This study employed a solvothermal method to prepare two Fe-MIL-88B metal–organic framework (MOF)-derived catalysts using triethylamine (TEA) or NaOH as deprotonation catalysts. The catalysts were analyzed using X-ray diffraction, N2-physisorption, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, H2 temperature-programed reduction, and thermogravimetric analysis and were evaluated for the Fischer–Tropsch synthesis performance. It was evident that the catalyst preparation in the presence of TEA produces a higher MOF yield and smaller crystal size than those produced using NaOH. The pyrolysis of MOFs yielded catalysts with different Fe particle sizes of 6 and 35 nm for the preparation in the presence of TEA and NaOH, respectively. Also, both types of catalysts exhibited a high Fe loading (50%) and good stability after 100 h reaction time. The smaller particle size TEA catalyst showed higher activity and higher olefin yield, with 94% CO conversion and a higher olefin yield of 24% at a lower reaction temperature of 280 °C and 20 bar at H2/CO = 1. Moreover, the smaller particle size TEA catalyst exhibited higher Fe time yield and CH4 selectivity but with lower chain growth probability (α) and C5+ selectivity.

Binding Fe-doped g-C3N4 on the porous diatomite for efficient degradation of tetracycline via photo-Fenton process

We fabricated iron-doped carbon nitride on a diatomite surface through a single-step polymerization (FGD-x, where x represents Fe loading content). The FGD-x efficiently degrades tetracycline hydrochloride by a collaborative photo-Fenton process. The FGD-3 (FeCl3 loading 75 mg) showed the best catalytic performance in TC degradation with minimal H2O2 (viz. 1 mmol/L) at a wide pH range (2.0–7.0). Under optimized conditions, the FGD-3 can degrade 98.3% of 20.0 mg/L TC at pH 4.0 within 100 min under visible light irradiation. The scanning electron microscopic and X-ray photon spectroscopic data show that iron is successfully doped on g-C3N4. Electrochemical impedance spectroscopy and transient photocurrent performance analyses confirmed that photogenerated electrons rapidly transfer at FGD-3 and solution interface. Free radical quenching experiments and electron spin resonance analysis show that h+, ∙O2-, and ∙OH can degrade TC efficiently. Besides, FGD-3 has an ultra-high catalytic activity and extremely low iron leaching after repeated use. The FGD-3 provides a feasible way to design a new photo-Fenton catalyst for the destruction of organic pollutants from water.

Boosting Amination of 1‐Octanol to 1‐Octylamine via Metal‐Metal Oxide Interactions in NixFe1/Al2O3 Catalysts

AbstractThe synthesis of 1‐octylamine, a primary platform molecule, remained a great challenge in catalysis. In this work, NixFe1/Al2O3 was used for direct amination of 1‐octanol to 1‐octylamine. Catalyst evaluation indicated that the promotion effect of Fe/Ni ratio on the catalytic amination activity followed a volcano curve while the selectivity to 1‐octylamine was positively correlated with the Fe loading. Compared with the Ni/Al2O3 catalyst, the amination activity was increased by 2.8 times by optimizing the Fe/Ni ratio to 0.33, and the selectivity to 1‐octylamine was increased from 84.0 % to 96.3 % when increasing the Fe/Ni ratio from 0 to 1. Based on catalyst characterizations, the good performance of NixFe1/Al2O3 was ascribed to the combined modification effect of the NiFe alloy and Ni−FeOx interface. The FeOx species enriched on the Ni particle surface provided sufficient Fe2+/Fe3+−O2− sites for the activation of 1‐octanol, and the cooperation between Ni sites and Lewis acid‐base pairs enhanced the amination of 1‐octanol to 1‐octylamine. This work sheds new light on the design of Ni‐based catalysts without using a noble metal for primary amine preparation.