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Fe/graphene oxide and Cu–Fe/graphene oxide nanocomposite were synthesized by the atomic implantation method to study the photocatalytic degradation of dichlorodiphenyltrichloroethane (DDT). The synthesized nanocomposites were characterized by the XRD, N2 isotherms, SEM with EDX, TEM and XPS analysis. Characterization results have reported that oxides of Cu and Fe were uniformly distributed on graphene oxide and exited in the form of Cu+ and Fe2+ ions in Cu–Fe/graphene oxide nanocomposite. The high photocatalytic DDT removal efficiency 99.7% was obtained for Cu–Fe/graphene oxide under the optimal condition of 0.2 g/L catalyst, 15 mg/L H2O2 and pH 5. It was attributed to the reduction of Fe3+ to Fe2+ by Cu+ ions and –OH radicals formation. However, it was dropped to 90.4% in the recycling study by leaching of iron and without a change in phase structure and morphology. [ABSTRACT FROM AUTHOR]

Catalytic ozonation is a new method used for removal of NH4OH solution. Therefore, high catalytic performance (activity and selectivity) should be achieved. In this work, we report the synthesis and catalytic performance of Fe2O3-Co3O4 modified dolomite in the catalytic ozonation of NH4OH solution. Dolomite was successfully activated and modified with Fe2O3 and Co3O4. Firstly, dolomite was activated by heating at 800°C for 3 h and followed by KOH treatment. Activated dolomite was modified with Fe2O3 by the atomic implantation method using FeCl3 as Fe source. Fe2O3 modified dolomite was further modified with Co3O4 by precipitation method. The obtained catalysts were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), N2 adsorption–desorption (BET), and temperature-programmed reduction (H2-TPR). From SEM image, it was revealed that nano-Fe2O3 and Co3O4 particles with the size of 80–120 nm. Catalytic performance of activated dolomite, Fe2O3 modified dolomite, and Fe2O3-Co3O4 modified dolomite in catalytic ozonation of NH4+ solution was investigated and evaluated. Among 3 tested catalysts, Fe2O3-Co3O4 modified dolomite has the highest NH4+ conversion (96%) and N2 selectivity (77.82%). Selectivity toward N2 over the catalyst was explained on the basis of bond strength M-O in oxides through the standard enthalpy Δ H ° f of oxide. Catalyst with lower Δ H ° f value has higher N2 selectivity and the order is the following: Co3O4 (Δ H ° f of 60 kcal (mole O)) > Fe2O3 (Δ H ° f of 70 kcal (mole O)) > MgO (Δ H ° f of 170 kcal (mole O)). Moreover, high reduction ability of Fe2O3-Co3O4 modified dolomite could improve the N2 selectivity by the reduction of NO3- to N2 gas. [ABSTRACT FROM AUTHOR]

Nickel-based heterogeneous catalysts have shown promising results in many industrial-scale catalytic reforming processes and hydrocarbon reforming reactions such as dry reforming of methane (DRM). However, it is also reported that Ni-based catalysts generally show less resistance to the carbonaceous deposition, which ultimately causes their rapid deactivation during the reaction. One possible solution to improve the coke resistance is the addition of a promoter to the catalyst, which has shown successful results to reduce the coke formation. Therefore, this study also aimed to prepare boron-promoted Ni-based catalysts and investigate their efficiency for DRM reactions. A series of different catalysts with 10% nickel and x% boron (x: 1%, 2%, 3%, and 5%) were prepared by using an ordered mesoporous silica as a support and tested in DRM. The results demonstrated that boron-promoted Ni/SBA-15 catalysts obtained significant catalytic activity for CH 4 and CO 2 conversions. Meanwhile, it was noticed that a lower concentration of boron (1 and 2%) was more favourable to achieve higher catalytic activity, whereas the higher concentration (3% and 5%) resulted in a comparatively lower conversion for CH 4 and CO 2. Evidently, the higher activity of 2% B-promoted catalyst was ascribed to the synergistic effect of high surface area and lower crystallite size that greatly improved the active sites accessibility. Moreover, the results confirmed 14% carbon deposition on unpromoted (NS) catalyst and it was reduced to 1.3% for 2% boron-promoted catalyst owing to the presence of B-OH species on catalyst surface. Image 1 • 1% and 2% of boron loadings decreased crystallite size of nickel. • Activity of catalysts showed a parallel relation to H 2 -uptake. • Low boron loading exhibited highest catalytic performance. • Coke formation was efficiently controlled by increasing boron loading (≥1%). [ABSTRACT FROM AUTHOR]

[Display omitted] • The flow reactor was employed for fructose dehydration to 5-HMF using acidic ionic liquids. • 1-(4-Sulfobutyl)-3-methylimidazolium bromide resulted in the maximum 5-HMF yield, which was achieved in 68.0% for 5 min. • The method showed environmentally friendly and practical synthesis of HMF. The application of continuous flow reactors for sustainable chemical research and production has attracted much attention. 5-Hydroxymethylfurfural (5-HMF) has been considered high potential for the production of chemicals and fuels. This work demonstrated the promise of synthesizing 5-HMF with high yield and selectivity using ionic liquids under continuous flow. The effects of temperature, solvent, catalyst activity, catalyst loading, substrate, and large-scale synthesis were investigated to choose the optimal reaction condition. As a result, 1-(4-sulfobutyl)-3-methylimidazolium bromide afforded 5-HMF in the good yield, about 68% in DMSO at 140 °C for 5 min. This approach is not only an eco-friendly pathway but also saves time, which can obtain high efficiency and apply in the large-scale production of 5-HMF from fructose. [ABSTRACT FROM AUTHOR]

• Microwave irradiation from a commercial microwave oven was used for a green, safe, simple, and effective process. • High yield and selectivity of 5-HMF from fructose were obtained using easily accessible and low-cost materials. • An easy method to synthesize efficient carbonaceous catalysts with high surface acidity from an abundant biomass source D-glucose. • The highest 5-HMF yield was achieved in 79.9% for 5 min using CC-oxa with the loading of 1 mg as catalyst in DMSO. Recently, the catalytic conversion of fructose to 5-hydroxymethylfurfural (5-HMF) has attracted much interest. The idea of a low-cost, sustainable, energy-efficient method is critical to obtain excellent yield and selectivity for the target product 5-HMF. In this work, microwave (MW) irradiation was chosen as a heating source for the conversion of fructose to 5-HMF with the presence of various amorphous carbons containing Brønsted acid sites as catalysts in dimethyl sulfoxide (DMSO) as a solvent. The catalysts' morphology, surface functional groups, thermal stability, and compositions of the obtained solids were examined by scanning electron microscope (SEM), elemental mapping, thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FT-IR), energy dispersive X-Ray spectroscopy (EDX), Raman spectroscopy and X-ray diffraction (XRD) techniques. The effect of solvent, heating technique, MW power, time, and catalytic loading on the reaction was studied thoroughly. The highest 5-HMF yield of 79.9% and 5-HMF selectivity of 79.7% were achieved with the optimal condition. 5-HMF was easily separated using a liquid-liquid extraction procedure with high purity. Moreover, the catalyst can be quickly recovered and reused. MW irradiation has proved to selectively and efficiently promote the formation of 5-HMF with high yield in a short reaction time. A mechanism for the formation 5-HMF from fructose was also proposed. [Display omitted] [ABSTRACT FROM AUTHOR]

3%Ce- and 3%La-promoted 10%Cu/Al 2 O 3 catalysts were synthesized via a sequential incipient wetness impregnation approach and implemented for ethanol CO 2 reforming (ECR) at 948–1023 K and stoichiometric feed ratio. CeO 2 and La 2 O 3 promoters reduced CuO crystallite size from 32.4 to 27.4 nm due to diluting impact and enhanced the degree of reduction of CuO → Cu0. Irrespective of reaction temperature, 3%La–10%Cu/Al 2 O 3 exhibited the highest reactant conversions, H 2 and CO yields followed by 3%Ce–10%Cu/Al 2 O 3 and 10%Cu/Al 2 O 3. The greatest C 2 H 5 OH and CO 2 conversions of 87.6% and 55.1%, respectively were observed on 3%La–10%Cu/Al 2 O 3 at 1023 K whereas for all catalysts, H 2 /CO ratios varying from 1.46 to 1.91 were preferred as feedstocks for Fischer-Tropsch synthesis. Activation energy for C 2 H 5 OH consumption was also reduced with promoter addition from 53.29 to 47.05 kJ mol−1. The thorough CuO → Cu0 reduction by H 2 activation was evident and the Cu0 active phase was resistant to re-oxidation during ECR for all samples. Promoters addition reduced considerably the total carbon deposition from 40.04% to 27.55% and greatly suppressed non-active graphite formation from 26.94% to 4.20% because of their basic character and cycling redox enhancement. Image 1 • 3%La–10%Cu/Al 2 O 3 exhibited high C 2 H 5 OH (87.6%) and CO 2 (55.1%) conversions. • Promoter addition reduced C 2 H 5 OH activation energy from 53.29 to 47.05 kJ mol−1. • CeO 2 and La 2 O 3 hindered carbon deposition from 40.04% to 27.55%. [ABSTRACT FROM AUTHOR]

• 10%Co/MA catalyst was modified by incorporation 3 wt% of Ce, La, Y, and Sm promoters. • Reactant conversion: YCo/MA > LaCo/MA > CeCo/MA > SmCo/MA > Co/MA. • YCo/MA showed the highest activity due to great Co dispersion and strong interaction. • Lowest coke recorded by YCo/MA attributed to the superior oxygen storage capacity. • Inferior activity of SmCo/MA due to its lower alkaline attributes. Co/mesoporous alumina (MA) catalysts promoted with Ce, La, Sm, and Y were evaluated via methane dry reforming. Co particle dispersion on MA was evidently improved after promoter incorporation, resulting in smaller crystallite size and lesser Co agglomeration. Unlike Ce and La promoters, the employment of Y and Sm promoters reduced catalyst reducibility by strengthening Co-MA interaction. The reactant conversions improved in the order of YCo/MA > LaCo/MA > CeCo/MA > SmCo/MA > Co/MA, while the amount of carbon deposit was recorded with the sequence of Co/MA > SmCo/MA > LaCo/MA > CeCo/MA > YCo/MA. Additionally, YCo/MA attained the highest activity (CH 4 conversion = 85.8%, CO 2 conversion = 92.2%) and possessed the lowest carbon deposition (7.02%) due to great Co dispersion, small Co particle size with strong Co-MA interaction and higher oxygen storage capacity. H 2 /CO ratios were obtained within 0.78–0.86, slightly lower than 1 in consequence of the reverse water–gas shift. [ABSTRACT FROM AUTHOR]

The novel nanostructured Ti 0.9 Ir 0.1 O 2 acting as a potential catalyst support for Pt in fuel cell applications was easily synthesized by means of a facile and simple low-temperature hydrothermal process without using any surfactants and further heat treatment. Interestingly, even in low iridium doping concentration, the Ti 0.9 Ir 0.1 O 2 support possessed the high electronic conductivity of 0.016 S/cm, which was ∼105 times as high as pure TiO 2 (4.15 × 10−7 S/cm), suggesting the efficient doping of iridium into TiO 2 lattice. Furthermore, the modified chemical reduction route utilized to prepare the 20 wt % Pt/Ti 0.9 Ir 0.1 O 2 electrocatalyst exhibited the good anchoring and uniform distribution of Pt nanoparticles (NPs) (∼3 nm) over Ti 0.9 Ir 0.1 O 2 surface and thus eventually resulted in the high electrochemical surface area (∼85.08 m2/gPt) compared to that of the commercial 20 wt % Pt/C (E-TEK) catalyst (∼69.21 m2/gPt). The cyclic voltammetry results in the methanol media revealed that the 20 wt % Pt/Ti 0.9 Ir 0.1 O 2 displayed the superior electrocatalytic activity compared to the 20 wt % Pt/C (E-TEK) catalyst towards the methanol electro-oxidation. For instance, the 20 wt % Pt/Ti 0.9 Ir 0.1 O 2 catalyst possessed the higher oxidation current density (∼28.8 mA/cm2), the lower onset potential (∼0.12 V) and the higher I f /I b ratio in comparison with the commercial 20 wt % Pt/C (E-TEK) catalysts. It is worth noting that the chronoamperometry results also indicated that the 20 wt % Pt/Ti 0.9 Ir 0.1 O 2 exhibited higher durability than the commercial 20 wt % Pt/C (E-TEK) catalyst. Beside introducing novel Ti 0.9 Ir 0.1 O 2 material, these results also offer a pathway of exploring the low dopants content of Ti x Ir 1-x O 2 material to serve as a good catalyst support for many fuel cell applications. • A facile green synthetic route for the preparation of the novel Ti 0.9 Ir 0.1 O 2. • The Ti 0.9 Ir 0.1 O 2 possessed high electronic conductivity with the low doping concentration. • Pt/Ti 0.9 Ir 0.1 O 2 has low onset potential for methanol oxidation reaction. • Pt/Ti 0.9 Ir 0.1 O 2 demonstrates high activity and durability for methanol oxidation. [ABSTRACT FROM AUTHOR]

Iron metal-framework MIL−88B(Fe) (chemical formula: Fe 3 O [C 6 H 4 (CO 2) 2 ] 3 OH.nH 2 O) has received much attention as a promising catalyst for the degradation of organic dyes. Unfortunately, some MOFs suffer from a deficiency of stability; thus, limiting their range of applications. To handle this problem, we attempted to replace Fe3+ ions with other metal ions at different ratios to improve the photocatalytic performance. Briefly, M/Fe−MOFs (M = Ni, Mg and Sn) with remarkably different properties were obtained using the microwave-assisted solvothermal method. The morphology of the synthesized bimetallic metal-organic frameworks was characterized by SEM and TEM; while their physical and chemical properties were defined by XRD, FT−IR, Raman, XPS, UV–vis DRS, and BET. The photocatalytic performance of the prepared materials was explored through the photocatalytic degradation of organic dyes (rhodamine B (RhB), crystal violet (CV), methyl orange (MO) and methylene blue (MB)) under irradiation of visible light was explored. The result showed that 10%Ni/Fe-MOF sample achieved above 96 % of RhB removal after 120 min of irradiation. The effects of pH solution, catalyst dosage and RhB concentration on RhB decomposition efficiency were carefully investigated. Furthermore, the present study has proposed a mechanism of RhB dye degradation reaction by bimetallic MOFs catalysts. Additionally, the free radical scavenging experiment has found that OH• and h+ radicals took the main responsibility for RhB decomposition. The stability and reliability of 10%Ni/Fe-MOF were also evaluated via the leaching and reusability tests. Interestingly, the photocatalyst performance experienced a negligible reduction after five consecutive usages. The results are expected to broaden the knowledge of bimetallic MOF synthesis and its applications. [Display omitted] • Bimetallic M/Fe−MOFs (M = Ni, Mg and Sn) were synthesized microwave-assisted solvothermal method • 10%Ni/Fe-MOF achieved above 96 % of rhodamine B (RhB) removal after irradiation for 120 min • A mechanism of RhB dye degradation reaction by bimetallic MOFs catalysts has been proposed • The photocatalyst performance experienced negligible reduction after five consecutive usages. [ABSTRACT FROM AUTHOR]

The modified Al-MCM-41 solid acids with turning Si/Al molar ratio were successfully fabricated through a hydrothermal route and utilized as a suitable catalyst in the cellulose conversion into 5-hydroxylmethylfurfural (5-HMF). The crystal structure, composition, morphologies and porosity of as-synthesized acids were characterized by XRD, FT-IR, N 2 adsorption-desorption, TEM and EDS. The 27Al MAS NMR and 29Si-MAS NMR results revealed the existence of both Al framework and Al extra framework. Besides, the existence of medium-weak and strong acid sites, according to Brønsted and Lewis acidity, in Al-MCM-41 acids was confirmed by NH 3 -TPD and FTIR-pyridine adsorption. The 30Al-MCM-41 solid acid (Si/Al molar ratio = 30) exhibited excellent activity with the highest 5-HMF yield of 40.56% compared to other samples. We also discovered that 5-HMF production, as well as cellulose conversion, strongly depended on the total acid, strong/medium-weak acid ratio, as well as Brønsted/Lewis acid ratio. Therefore, these parameters have been considered as essential factors for the design of solid acid for 5-HMF production. Image 1 • Al-MCM-41 with turning Si/Al molar ratio was fabricated by a hydrothermal router. • The existence of Brønsted/Lewis acidity was confirmed by NH 3 -TPD and FTIR-pyridine. • Al-MCM-41 was used as effective solid acids for 5-HMF fabrication from cellulose. • The total acid and strong/medium-weak acid ratio affected the 5-HMF selectivity. • 5-HMF selectivity strongly depended on the Brønsted/Lewis acid ratio. [ABSTRACT FROM AUTHOR]

• Bimetallic Al/Fe Metal-Organic Framework (Al/Fe-MOF) was synthesized by the microwave-assistant method. • Al/Fe-MOF showed excellent photocatalytic activity with the rate constant of 2.8 × 10−2 min−1. • Al/Fe-MOF showed high stability after three cycles. • The reaction mechanism of rhodamine B photodegradation process over Al/Fe-MOF also investigated. MIL–88B(Fe) (MIL: Materials Institute Lavoisier) and bimetallic Al/Fe Metal-Organic Framework (Al/Fe-MOF) were synthesized by the microwave-assistant method. The as-synthesized samples were used as an effective catalyst for photo-Fenton degradation of rhodamine B (RhB) under visible light irradiation. The Al/Fe-MOF catalyst caused to degrade more than 96% of RhB in up to 120 min with the rate of reaction reached 2.8 × 10−2 min−1, while the rate achieved using MIL–88B(Fe) reached 1.2 × 10−2 min−1. Besides, the reaction mechanism of RhB photo-Fenton degradation process over Al/Fe-MOF also investigated. These results indicate that Al/Fe-MOF has been considered as a potential catalyst for wastewater treatment. [ABSTRACT FROM AUTHOR]