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Flower-like cobalt–molybdenum mixed-oxide microspheres (CoMo-FMs) with hierarchical architecture were successfully synthesized via a hydrothermal process and subsequent calcination step. The characterization results show that CoMo-FMs were assembled from ultrathin mesoporous nanosheets with thicknesses of around 4.0 nm, providing the composite with a large pore volume and a massive surface area. The synthesized CoMo-FMs were employed as catalysts for the aerobic oxidative desulfurization (AODS) of fuel, and the reaction results show that the optimal catalyst (CoMo-FM-2) demonstrated an outstanding catalytic performance. Over CoMo-FM-2, various thiophenic sulfides could be effective removed at 80–110 °C under an atmospheric pressure, and a complete conversion of sulfides could be achieved in at least six consecutive cycles without a detectable change in chemical compositions. Further, the catalytic mechanism was explored by conducting systemic radical trapping and transformation experiments, and the excellent catalytic performance for CoMo-FMs should be mainly due to the synergistic effect of Mo and Co elements. [ABSTRACT FROM AUTHOR]

Selective semi-hydrogenation of acetylene is an extremely important reaction from both industrial and theoretical perspectives. Palladium, due to its unique chemical and physical properties, is the most active and currently irreplaceable metal for this reaction in industry, but the poor catalytic selectivity towards ethylene is also its inherent shortcoming. Introducing a secondary metal to tune a geometric and electronic structures of Pd nanoparticles and to create a synergistic effect is the most widely used strategy to effectively improve the overall catalytic performance of Pd-based catalysts. Thus, various supported Pd-based bimetallic catalysts for selective semi-hydrogenation of acetylene have been exploited in the past decade. Timely comparison, analysis, and summarizing of various preparation methods may offer a beneficial reference for the subsequent development of such catalysts. In this context, herein, the advances in synthesis strategies of catalysts, including nano-catalysts, single atom alloys (SAAs), as well as bimetallic dual atom catalysts are summarized systematically. Their advantages and disadvantages are comparatively discussed. Finally, future perspectives for the synthetic strategies of supported Pd-based bimetallic catalysts for selective semi-hydrogenation of acetylene are proposed. [ABSTRACT FROM AUTHOR]

Novel zinc–palladium–porphyrin bimetal metal–organic framework (MOF) nanosheets were directly synthesized by coordination chelation between Zn(II) and Pd(II) tetra(4-carboxyphenyl)porphin (TCPP(Pd)) using a solvothermal method. Furthermore, a serial of carbon nanosheets supported Pd–Zn intermetallics (Pd–Zn-ins/CNS) with different Pd: Zn atomic ratios were obtained by one-step carbonization under different temperature using the prepared Zn-TCPP(Pd) MOF nanosheets as precursor. In the carbonization process, Pd–Zn-ins went through the transformation from PdZn (650 °C) to Pd3.9Zn6.1 (~950 °C) then to Pd3.9Zn6.1/Pd (1000 °C) with the temperature increasing. The synthesized Pd–Zn-ins/CNS were further employed as catalysts for selective hydrogenation of acetylene. Pd3.9Zn6.1 showed the best catalytic performance compared with other Pd–Zn intermetallic forms. [ABSTRACT FROM AUTHOR]

A one-pot and green synthesis methodology was successfully designed to prepare nitrogen-doped carbon (NC) cohered Fe3O4 nanoparticles with rich oxygen vacancies (Fe3O4-OVs/NC). The preparation was achieved via cold-atmospheric-pressure air plasma using Fe2O3 nanoparticles as the only precursor, and pyridine as the carbon and nitrogen source. Systematic characterization results of the as-prepared Fe3O4-OVs/NC confirmed the transition from Fe2O3 to Fe3O4, along with the generation of oxygen vacancies, while preserving the original needle-like morphology of Fe2O3. Moreover, the results indicated the formation of the NC attaching to the surface of the formed Fe3O4 nanoparticles with a weight percent of ~13.6%. The synthesized nanocomposite was further employed as a heterogeneous Fenton catalyst to remove phenol from an aqueous solution. The material has shown excellent catalytic activity and stability, demonstrating a promising application for wastewater treatment. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • CVD temperature has a significant effect on the structure of the formed carbon. • Graphene-like carbon films can be fabricated at low CVD temperatures. • The graphene-like films show similar structure of reduced graphene oxides. • Graphene-like carbon films possess enhanced reactivity with hydrogen and CO 2. Abstract The formation and reactivity of carbon on the supported nickel catalyst is a key issue for the low temperature activity and stability with methanation, reforming and other reactions. In this work, Ni(1 1 1)/TiO 2 was prepared and applied as the catalyst to deposit carbon using low temperature chemical vapor deposition (CVD) of carbon monoxide. It was found that the CVD temperature could significantly affect the formation of carbon. With the CVD temperature decreasing, the disorder of the carbon increased, while the degree of graphitization was reduced. As a result, graphene-like films can be obtained at low CVD temperatures (from 300 to 350 °C). Such carbon films show a significantly improved reactivity with hydrogen and carbon dioxide. This explains the excellent low temperature activity and stability for CO 2 or CO methanation over Ni catalysts with Ni(1 1 1). [ABSTRACT FROM AUTHOR]

A series of Co 3 O 4 /HZSM-5 catalysts with different Co 3 O 4 loadings were prepared by incipient wetness impregnation followed by thermal calcination or dielectric barrier discharge (DBD) plasma decomposition. Their catalytic performances for the complete combustion of methane were evaluated from 300 to 700 °C. The plasma decomposed samples exhibit much higher catalytic activity than the calcined ones. Among all the samples tested, the plasma decomposed catalyst with 20 wt.% loading of Co 3 O 4 possesses the highest catalytic activity with T 10 (10% CH 4 conversion) at 300 °C and T 100 (complete conversion) at 550 °C. The excellent catalytic activity of the DBD plasma decomposed samples would attribute to well-dispersed Co 3 O 4 , enhanced low-temperature reducibility, high content of lattice oxygen and adsorbed oxygen species, as well as the low formation tendency of the intermediate of Co-formate. [ABSTRACT FROM AUTHOR]

Abstract: The binding of myricetin to lysozyme (Lys) in aqueous solution was investigated by fluorescence spectroscopy, ultraviolet–visible absorption spectroscopy (UV) and circular dichroism (CD) spectra under physiological conditions. There are also many metal ions present in body, thus the research about the effect of metal ions on the interaction of drugs with proteins is crucial. In this study, we have investigated the effect of both familiar metal ions Cu2+ and Fe3+ on the interaction between myricetin and Lys by using spectroscopy technique at pH 7.40, for the first time. Spectrophotometric observations are rationalized in terms of a static quenching process in a static quenching way. The cause of showing upward curvy patterns in Stern–Volmer plots was analyzed. The binding constants and binding sites of myricetin with Lys with or without Cu2+ and Fe3+ at different concentrations of myricetin were calculated. UV/vis measurements on the enzymatic activity of Lys with or without Cu2+ in the absence or presence of myricetin indicated that the interaction between myricetin and Lys led to a reduction in the activity of Lys. Furthermore, the effect of pH on the binding constant of myricetin with Lys was also examined. [Copyright &y& Elsevier]

Aerobic oxidative desulfurization (AODS) promises a sustainable alternative desulfurization process for fuel, yet is still limited by high temperature and low efficiency for oxygen activation. Here we report that the monolayer two-dimensional vanadium carbide (V2CTx) MXene can emerge as a robust and stable catalyst for the oxidation of thiophenic compounds with oxygen in air as an oxidant. The catalyst performs a higher mass specific activity over the state-of-art vanadium oxides, activates the reaction at 70 °C, and achieves effective conversion of various sulfides under mild condition. Coupling characterizations with DFT calculations, we reveal that the abundant low valence V species accompanied anion vacancies on the surface of MXene have excellent oxygen activation capacity, which well explains its outstanding catalytic performance at low temperature. Moreover, the catalyst maintains its activity after 6 cycles of reuse, and is expected to act as a sustainable, efficient and stable AODS catalyst. [ABSTRACT FROM AUTHOR]

Abstract: The binding reaction between vitamin B12 (B12, cyanocobalamin) and lysozyme (Lys) has been investigated by fluorescence, synchronous fluorescence, ultraviolet–vis (UV) absorbance, and three-dimensional fluorescence. The intrinsic fluorescence of Lys was strongly quenched by the addition of B12 in different pH buffer solutions (pH 3.4, 7.4, and 9.0) and the spectroscopic observations are mainly rationalized in terms of a static quenching process at lower concentration of B12 (C B12/C Lys <5) and a combined quenching process at higher concentration of B12 (C B12/C Lys >5). The structural characteristics of B12 and Lys were probed, and their binding affinities were determined under different pH conditions (pH 3.4, 7.4, and 9.0). The effect of B12 on the conformation of Lys was analyzed using UV, synchronous fluorescence and three-dimensional fluorescence under different pH conditions. These results indicate that the binding of B12 to Lys causes apparent change in the secondary or tertiary structures of Lys. Furthermore, the effect of Zn2+ on the binding constant of B12 with Lys under various pH conditions (pH 3.4, 7.4, and 9.0) was also studied. [Copyright &y& Elsevier]

Based on the synergy between MoP and N-doped carbon, MoP nanoparticles encapsulated in N-doped carbon hollow spheres were synthesized using inorganic-organic hybrids as precursors, which shows an excellent stability and activity with an overpotential 96 mV at 10 mA cm−2 and a small Tafel slope of 53 mV dec−1 in alkaline solution. [Display omitted] • A template-free approach was developed to fabricate MoP@NC hollow microsphere. • Inorganic-organic hybrids were used as precursors. • Remarkable electrocatalytic hydrogen evolution performance could be achieved. • The synergy between MoP and the pyridinic N could optimize the electronic structure. Encapsulating transition metal phosphides into nitrogen-doped carbon (NC) materials is an effective strategy to enhance the electrocatalytic performance. Herein, we develop a novel template-free approach to rationally fabricate molybdenum phosphide (MoP) nanoparticles encapsulated in N-doped carbon (MoP@NC) hollow microspheres for alkaline hydrogen evolution reaction (HER) by employing inorganic-organic hybrids as precursors, in which phosphorus source of the MoP@NC derives from tetra (hydroxymethyl) phosphorus chloride for the first time. The optimized MoP@NC sample shows a low overpotential of 96 mV at 10 mA cm−2, a small Tafel slope of 53 mV dec−1, and excellent stability. The enhanced HER performance is mainly attributed to the integrated effects of a distinctive hollow structure, high pyridinic N-doping level, and the extremely intimate synergy between MoP and NC. Theoretical calculations indicate that the active sites of the catalyst are mainly located at Mo atoms adjacent to the pyridinic N-doped carbon layer (pyridinic-N-MoP); the synergistic interaction between MoP and pyridinic N (rather than pyrrolic or graphitic N) atoms can lower the d band center of Mo, weaken the Mo-H ads bond and thereby enhance HER performance. In addition, the pyridinic N atoms at the interactive sites play a key role in adsorbing H 2 O and preventing the adsorption of OH*, resulting in accelerating the water splitting. This work provides a new method to rationally synthesize high-efficient and stable MoP-based hollow sphere electrocatalysts for alkaline HER through designing inorganic-organic hybrid precursors. [ABSTRACT FROM AUTHOR]

• A sulfonated biochar is prepared by sulfonation method of 4-chlorobenzenesulfonic acid. • The sulfonated biochar have a strong hydrophobic network and acid density. • The catalyst is highly active for the esterification reactions. • The catalyst is active and selective for alkylation reactions. • The catalyst is stable for five runs. Catalytic esterification of fatty acid with methanol, alkylation of 4-ethylphenol with benzyl alcohol as well as 2-methylfuran with cyclopentanone are of great significant for the production of biofuels. However, the in-situ produced water decreases the acidity of catalyst and induces side reaction, leading to an unsatisfactory catalytic activity and selectivity. Herein, a novel biochar-based hydrophobic benzenesulfonic acid is prepared for the first time by one-pot sulfonation method of biochar with 4-chlorobenzenesulfonic acid. It has a large specific surface area of 100-400 m2/g, a hydrophobicity with H 2 O contact angle higher than 110° and a high concentration of sulfonic acid over 1.0 mmol/g. In the esterification reaction of fatty acid with methanol for synthesis of biodiesel, it shows a higher conversion of 96.0% than sulfonic acid resin amberlyst-15 (86.7%) and traditional sulfonated biochar-SO 3 H (28.0%). In the alkylation reaction of 4-ethylphenol with phenylmethanol/2-methylfuran with cyclopentanone for high-density bicyclic/monocyclic biofuel, its catalytic efficiency with target product yields are 69.4% and 70.5% respectively, which are also higher than that of amberlyst-15 (74.3%, 49.4%) and biochar-SO 3 H (14.7%, 13.0%). Furthermore, the catalyst is more stable than biochar-SO 3 H. The preparation of hydrophobic biochar-based sulfonic acid catalysts not only opens a new way for high-value utilization of biochar, but also provides a novel efficient catalyst in many acid-catalyzed transformation reactions that the product H 2 O causes deleterious effects. [ABSTRACT FROM AUTHOR]

• Ni/CeO 2 is successfully prepared by plasma decomposition of nickel precursor. • The obtained Ni/CeO 2 catalyst shows a significantly high activity at low temperatures. • A up to 99.5 % methane selectivity was achieved. • In-situ XAS, XRD, and XPS characterizations were conducted. • Small Ni size, strong Ni-CeO 2 interaction and rich interfacial sites causes high activity. A Ni/CeO 2 catalyst was prepared via decomposition of nickel precursor by gas discharge plasma, followed by hydrogen reduction thermally. The activity of the obtained catalyst reaches the highest level towards CO 2 methanation with methane selectivity above 99 % at reaction temperatures lower than 300 °C. For example, the CH 4 formation rate at 275 °C is 100.3 μmol g cat −1 s−1, higher than the reported catalysts at the same reaction temperature. Characterization results indicate that the plasma decomposition leads to an interfacial structure where Ni atoms bind with O atoms from ceria. A strong metal-support interaction is caused. Rich interfacial Ni-CeO 2 sites are thus formed with excellent redox property. The unique interfacial structure confines small nickel particles on the ceria surface, exposing more metallic Ni as active sites for splitting H 2. Therefore, the plasma prepared Ni/CeO 2 catalyst shows balanced active sites for H 2 splitting and CO 2 activation, improving low temperature catalytic activity significantly. [ABSTRACT FROM AUTHOR]