The NiO/NiS composite catalyst synthesis is designed using a simple and facile method. Composite materials with different sulfur sources were characterized and applied for catalytic reduction of 4nitrophenol (4-NP) in aqueous solution. The catalysts' universality towards reduction/decolorization of other organic dyes such as methylene blue (MB), methyl orange (MO), and rhodamine B (RhB) was eva...

We describe a three-step bromine-mediated process for oxidative coupling of methane using O2 as oxidant. In the first step, a supported metal bromide solid is treated with O2 to generate Br2 and supported metal oxide. The Br2 thus formed reacts with excess CH4, giving a mixture of CH4, bromomethanes, and HBr. This mixture is passed over a CaO/zeolite composite which condenses bromocarbons with ...

The ‘intelligent catalyst’ concept, involving cyclical movement of precious metal atoms in and out of a perovskite oxide lattice, was proposed by Nishihata et al. in 2002, and the precious metal atom (Pd) was then believed to occupy the B site in the perovskite (LaFeO3) lattice, based on X-ray anomalous diffraction measurements [1]. Since then, B site occupancy has generally been assumed for al...

Y-junction carbon nanocoils (Y-CNCs) were synthesized by thermal chemical vapor deposition using Ni catalyst prepared by spray-coating method. According to the emerging morphologies of Y-CNCs, several growth models were advanced to elucidate their formation mechanisms. Regarding the Y-CNCs without metal catalyst in the Y-junctions, fusing of contiguous CNCs and a tip-growth mechanism are consid...

The long-term stability of supported metal catalysts designed for solid-oxide fuel cell (SOFC) anodes is evaluated using a phase field simulation approach. Porous support structures are numerically sintered and then infiltrated with a nanoscale catalyst phase to mimic scaffolds fabricated via both pyrolysis and acid leaching techniques. Simulations capture the dewetting, particle agglomeration,...

Surface-science investigations have contributed significantly to heterogeneous catalysis in the past several decades. Fundamental studies of reactive systems on metal single crystals have aided researchers in understanding the effect of surface structure on catalyst reactivity and selectivity for a number of important reactions. Recently, model systems, consisting of metal clusters deposited on...

Catalytic wet air oxidation is a promising alternative for the treatment of phenolic waste water which cannot be treated in conventional sewage plants. Catalytic wet air oxidation of an aqueous phenol solution was conducted in a ®xed bed reactor operating in trickle ̄ow regime. Either active carbon or a commercial copper oxide supported over -alumina was used as catalyst. The performance of bot...

Reduced graphene oxide (rGO), as a newly emerged carbon material, has attracted great attention concerning its applications for electrocatalysts. Presently, there are mixed opinions regarding the advantages to using rGO as a support for preparing nonprecious metal catalysts for the oxygen reduction reaction (ORR). The primary goal of this work is to determine whether rGO would be favorable for ...

In our current study, supercritical water impregnation (SCWI) was introduced as a unique catalyst preparation method by employing the high diffusivity property of supercritical water. The method allows nano-particles to place on support surfaces in extremely dispersed conditions. The silica-based nanocatalyst granules for this purpose were prepared by initial impregnation of highly porous silic...

We report the application of palladium nanoparticles and thin films for hydrogen sensor. Electrochemically grown palladium particles with spherical shapes deposited on Si substrate and sputter deposited Pd thin films were used to detect hydrogen at room temperature. Grain size dependence of H(2) sensing behavior has been discussed for both types of Pd films. The electrochemically grown Pd nanop...