Utilization of Greenhouse Gases for Syngas Production by Dry Reforming Process Using Reduced BaNiO3 Perovskite as a Catalyst

For the commercialization of syngas production, the utilization of greenhouse gases and the fabrication of an active catalyst for the dry reforming methane (DRM) process are the biggest challenges because of deactivation by carbon deposition, oxidation, sintering, and loss of active surface sites under high temperature. In the present article, BaNiO3 perovskite was synthesized by the coprecipitation method, and its reduced form (r-BNO) was utilized for syngas production by the DRM reaction. It was found that the r-BNO showed high stability and good resistance against carbon deposition, however, the conversions (CH4 and CO2) have been found to be less than 50%. Many techniques such as TGA, XRD, FT-IR, UV-Vis, BET, SEM, TEM, XPS, TPR, TPO, and TPD were used in order to investigate the physical properties and evaluation conditions for syngas production. From the obtained results, it was revealed that BaNiO3 perovskite possessed a hexagonal crystal structure and perforated–rough surface; in addition, its structure was virtually regenerated by oxidation of the r-BNO catalyst, which provides a convenient way to regenerate the original catalyst in an oxidative atmosphere. Structural and surface alterations of the used catalyst, after the DRM reaction, were characterized by using TGA, TPO, and TEM, and it was found that there was no significant deposition of inert carbons (D and G) and deactivation of the r-BNO catalyst.

MBE growth of AlGaAs/Ge/AlGaAs core-shell nanowire

Heterostructured AlGaAs/Ge/AlGaAs core-multishell nanowires having hexagonal crystal structure were synthesized by molecular beam epitaxy. Formation of 2-3 nm Ge quantum well structure was demonstrated. Raman characterization revealed a 200 cm−1 peak corresponded to hexagonal phases of germanium.

STUDY OF STRUCTURAL AND ELECTROCHEMICAL PROPERTIES OF 3-D MICROFLOWER-LIKE NICKEL HYDROXIDE

Recent work reported on nickel hydroxide chemically synthesized by simple cast effective chemical bath deposition method at room temperature. During reaction, nanoflakes developed and time enhance nanoflakes interlinked to form marigold like microflower which reveals from SEM. Structural properties analysis by XRD and FT-IR gives hexagonal crystal structure and presence of Ni-O bond to confirmation of deposition of Ni(OH) material. Highest value of specific 2 -1 capacitance of electrode at deposition time 90 min without aniline from Cyclic voltammetry is 553 Fg at scan rate 10 mV -1 -1 -2 -1 -1 s and from Galvanostatic charge discharge 215 Fg at current density 3 mA cm with 6.04 W h kg and 1687.5 W kg of energy and power density respectively. EIS analysis reveals least charge transfer resistance of 90min deposition time electrode.

STRUCTURAL AND ELECTROCHEMICAL PROPERTIES OF CHEMICALLY DEPOSITED COPPER DOPED NICKEL HYDROXIDE

Present work reported, copper doped Ni(OH) deposited successfully by chemical bath deposition method on 2 economical stainless steel electrode. The XRD analysis represent hexagonal crystal structure and presence of Ni and Cu confirm by FT-IR study. The surface morphology studied by SEM indicates nanopetals linked marigold like microflowers. -1 -1 The 0.2% Cu doped Ni(OH)2 shows specific capacitance 715 Fg at scan rate 10 mV s . EIS study interprets that electrode N-0.2% have least charge transfer resistance which improve value of specific capacitance. All results revels cupper is good dopant for improve the specific capacitance.

Microstructural Investigation of Fluoroapatite Hydrothermally Converted from Hydroxyapatite Synthesized from Crocodile Eggshell

Fluoro/hydroxyapatite (FHAp) were prepared by hydrothermal at 150 °C for 24 hours with different of starting materials. The conversion of hydroxyapatite (HAp) and tricalcium phosphate to FHAp showed the rod-like shape with 200 nm. While, the morphology of FHAp from crocodile eggshell as CaCO3 form with different in phosphorus and fluoride source showed the unique structure evolution from rod-like hexagonal crystals, dumbbell to ball shape. Two distinctive morphology, first when using NaF as fluoride source with (NH4)2HPO4 precursor show the large cubic structure in high magnification it is tufted hexagonal crystal and it bundle like structure. As the pH value decreases in NH4F, it increases crystal size. For H3PO4 as phosphate precursor found that unique structure evolution from rod-like hexagonal crystals to dumbbell structure and then form the sphere assembly with a size of several micrometers.

STRUCTURE AND MECHANICAL PROPERTIES OF POWDERS OBTAINED BY ELECTRODISPERGING COBALT-CHROMIUM ALLOY

The work presents the results of attestation of powders that were obtained from the KHMS "Cellite" alloy (Co - 63%, Cr - 27%, Mo - 5%, Ni - 2%, Fe - 2%) by electroerosive dispersion under various technological conditions (voltage from 100 V to 220 V, the capacitance of condenser from 15 μF to 50 μF, pulse frequency from 100 Hz to 200 Hz), and with using working fluids of different chemical composition and properties (water, kerosene, butyl alcohol). The study of the dispersion of the obtained powders, based on the results, established: the range of particle sizes is from 20 μm to 110 μm depending on the production modes. The results show various particle sizes, both a few nanometers and hundreds of microns. Depending on the technological modes of production, various mechanisms of the formation of powder particles can occur. Flake particles ranging in size from a few nanometers to (as a rule) one micron are obtained by the crystallization of the material vapor. They usually form agglomerates or stick to larger particles. Spherical and elliptical particles with a diameter from tens of nanometers to hundreds of microns were formed in crystallized material upon melting. The result of thermal and mechanical action during electroerosive dispersion was fragmentation grains with an average size from units to hundreds of microns. To meet the requirements for powders used in additive machines, it is necessary to select modes that exclude brittle destruction of the particles of the powder material and ensure the production of spherical or elliptical particles in the required particle size ranges. As a result of the experiment during the study of the phase composition of powders, using various technological modes and the composition of working fluids, the following phases were revealed: Cobalt (Co) with a cubic crystal lattice, a = b = c = 3.561079 Å; Chromium (Cr) with a hexagonal crystal lattice a = b = 2.738459 Å, c = 4.55078 Å; Nickel (Ni) with a hexagonal crystal lattice, a = b = 2.652590 Å, c = 4.380519 Å; sigma-Cr7Co3 (Cr7Co3 with a tetragonal crystal lattice, a = b = 8.656172 Å, c = 4.484030 Å; Cobalt Iron (CoFe), with a cubic crystal lattice, a = b = c = 2.846754 Å; Chromium Carbide (Cr3C2) with an orthorhombic crystal lattice: a = 2.821Å, b = 5.53Å and c = 11.47Å; Iron (Fe) with a cubic crystal lattice, a = b = c = 3.604293 Å; Cobalt Carbide (Co3C), with an orthorhombic crystal lattice, a = b = 4.455931 Å, c = 6.86598 Å; Cobalt Oxide (CoO) with a cubic crystal lattice a = b = c = 4.563279 Å; Magnetite (Fe3O4) with a cubic crystal lattice a = b = c = 8.4774342 Å.