Enhancing the Dispersion of Cu-Ni Metals on the Graphene Aerogel Support for Use as a Catalyst in the Direct Synthesis of Dimethyl Carbonate from Carbon Dioxide and Methanol.

Graphene has attracted attention because of its interesting properties in catalyst applications including as a catalyst support; however, it is known that the graphene can be restacked, forming a graphite-like structure that leads to poor specific surface area. Hence, the high-porosity graphene aerogel was used as a Cu-Ni catalyst support to produce dimethyl carbonate (DMC) from carbon dioxide and methanol. In this work, we have introduced a new synthesis route, which can improve the dispersion of metal particles on the graphene aerogel support.

Roles of ZnO in Cu/Core-Shell Al-MCM-41 for NO Reduction by Selective Catalytic Reduction with NH: The Effects of Metal Loading and Cu/ZnO Ratio.

Cu-ZnO/Al-MCM-41 catalysts were studied for NO reduction. The total metal loading was varied as 3, 5, and 7 wt %, whereas the Cu-to-ZnO ratio was fixed at 1:1. Too high metal loading led to lower reducibility of Cu, as CuO and ZnO covers on the catalyst surface could partially block pores and hinder gas molecules to access the Cu ions.

Promotional Effects of Zn Doping on Cu/Core-Shell Al-MCM-41 for Selective Catalytic Reduction of NO with NH₃.

A Cu-Zn/core-shell Al-MCM-41 catalyst with various Cu and Zn species was investigated for selective catalytic reduction of NO with NH₃. The roles of Zn in the NO adsorption properties and the acidity of the catalysts were studied by temperature-programmed desorption of NO and Fourier transform infrared spectroscopy of NO+O₂ adsorption and NH₃ adsorption. The presence of Zn can promote the number of acid sites and improve the NO adsorption capacity by providing the additional sites for NO adsorption and subsequent nitrite and nitrate formation.

Role of Copper and Cerium on Core-Shell Al-MCM-41 in NO Reduction via a SCR-CH₄.

Copper species in the structure of Cu/core-shell Al-MCM-41 catalysts prepared by different techniques of Cu loading-substitution (S), ion-exchange (E), and impregnation (I) methods-were tested for NO reduction via a selective catalytic reaction with methane. Cerium was added to enhance the performance of copper. It was found that the 1.

High-Performance Asymmetric Supercapacitors of MnCoO Nanofibers and N-Doped Reduced Graphene Oxide Aerogel.

The working potential of symmetric supercapacitors is not so wide because one type of material used for the supercapacitor electrodes prefers either positive or negative charge to both charges. To address this problem, a novel asymmetrical supercapacitor (ASC) of battery-type MnCoO nanofibers (NFs)//N-doped reduced graphene oxide aerogel (N-rGO) was fabricated in this work. The MnCoO NFs at the positive electrode store the negative charges, i.

Synthesis of Copper-Based Nanostructured Catalysts on SiO2-Al2O3, SiO2-TiO2, and SiO2-ZrO2 Supports for NO Reduction.

The selective catalytic reduction of NO over a series of Cu-based catalysts supported on modified silica including SiO2-Al2O3, SiO2-TiO2, and SiO2-ZrO2 prepared via a sol-gel process and a flame spray pyrolysis (FSP) was studied. The prepared catalysts were characterized by means of TEM, XRD, XRF, TPR, and nitrogen physisorption measurement techniques, to determine particle diameter, morphology, crystallinity, phase composition, copper reducibility, surface area, and pore size of catalysts. The particles obtained from sol-gel method were almost spherical while the particles obtained from the FSP were clearly spherical and non-porous nanosized particles.

Low temperature synthesis of N-doped TiO2 nanocatalysts for photodegradation of methyl orange.

N-doped TiO2 nanoparticles were synthesized using a hydrazine-assisted liquid method at low temperatures, owing to the additional heat provided by the decomposition of hydrazine nitrate, which was formed by reaction of hydrazine with nitric acid. Different crystal phases of N-doped TiO2 were studied by varying the nitric acid concentration, and calcination temperature and time. These photocatalysts were characterized using a transmission electron microscope, UV-vis photometer, X-ray diffractometer, and nitrogen adsorption.

Effect of core-shell structure and chitosan addition on catalytic activities of copper-containing silica-aluminosilicate composites in deNO(x) reaction by H2.

Mesoporous silica-aluminosilicate composites were used as supports for selective catalytic reduction of NO by H2 using copper catalyst. Effect of loading techniques and structures of the supports on the catalytic performance were investigated. The nature, the oxidation state of copper, the structural properties and the morphology of the catalysts were characterized by means of UV-vis spectra, Fourier Transform Infrared Spectroscopy (FTIR), nitrogen sorption, and transmission electron microscopy, respectively.

Quench-ring assisted flame synthesis of SiO2-TiO2 nanostructured composite.

A flame aerosol reactor (FLAR) was used to synthesize SiO2-based nanocomposite materials of SiO2-TiO2 in different precursor molar ratios and quench ring positions. Processing conditions were determined that resulted in formation of different crystal phases at different precursor concentration molar ratios. The results showed that the addition of SiO2 inhibited TiO2 phase transformation from anatase to rutile.