Papers by Keyword: Metal Catalyst

Abstract: By isothermal chemical vapor infiltration (ICVI) preparation of carbon/carbon composites, We found fibrous materials with silver metallic luster in CVI furnace graphite cylinder outer wall, fiber diameter is 1 ~ 2 mm, length is 4 ~ 15 mm. The characterization of fibrous material have been systematically studied by scanning electron microscopy (SEM),element analysis, energy dispersive X-rays spectroscopy (EDS).After 2300 degrees heat treatment, the fibrous material were characterized by ultra-violet laser Raman spectroscopy. The SEM examination shows that these fibrous materials have a spherical top, the cross-section reveals a unique structure in which layers like growth rings lie concentrically on top of each other. The EDS analysis show the main element of fibrous material is carbon and a small amount of metallic element. Raman spectra show after 2300°C high temperature treatment ,the carbon fibrous material transformed from layer structure to graphite structure.

Abstract: In generally, the metal catalyst which synthesis by conventional techniques is usually in metal oxide form or easily oxidize in the air thus the metal catalyst must reduce to metallic form before using. It was complex process and dangerous. In the research, Carbon material from cattail flower (CF) were used as supporter of Nickel/Carbon supported metal catalyst (Ni/C). This research were studied effect of used carbon material from CF as supporter of Ni/C and varying nickel loading. The Ni/C catalyst were prepared by hydrothermal, impregnation and calcination process. Firstly, Dried CF has been pretreat via hydrothermal process with optimized condition at 180°C for 8h. Then, the nickel solution was added to support via impregnation method by varying Ni loading from 20 to 60 wt% of supported. Finally, the sample has been pelleted into 0.5mm-Ni/C pellet and calcined at 900°C for 2h under nitrogen atmosphere. Ni/C were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), Energy dispersive X-ray (EDX), surface area and pore size distribution was determined by N2 adsorption. The result indicate that nickel particle on Ni/C were in the free metal from without reduction and well dispersed on supported surface. Particle size and surface area of Ni/C were decreases at the increase metal loading. Nickel/Carbon supported metal catalyst were ready to use and could be controlled particle size, surface area and crystallinity by metal loading.

Abstract: In this paper, the conversion of biomass-derived glycolide to ethylene glycol over Cu was investigated. As a result, Cu showed significant catalytic role for the conversion of glycolide into ethylene glycol compared to other catalysts, such as Ni and Mo. A 24.3% yield of ethylene glycol was achieved in the process. The possible formation pathway of ethylene glycol from glycolide over Cu under hydrothermal conditions was proposed.

Abstract: The purpose of this study is to investigate the catalytic effects of different metals in Shengli lignite on the char reactivity. The pyrolysis of Shengli lignite and various metal catalyst loaded coal was investigated in a small fixed-bed reactor, and the gasification activity with steam for different chars was compared as well. The results show that Fe, Ni, Ca and K could effectively lowering the gasification temperature, enhancing the gasification reactivity of SL char. Alkali (K) and alkaline earth (Ca) could be feasibly used as catalysis for the catalytic steam gasification at relatively low temperatures (550~700°C) to produce gases with high H₂ (63.2~63.8 v%) and low CO (below 0.9%), and promoting the carbon-water reaction, the water-gas shift reaction to some extent.