Huali Long

Ni-Co/Mg-Al catalyst derived from hydrotalcite-like compound prepared by plasma for dry reforming of methane

Abstract Ni-Co bimetallic catalysts with different Ni/Co content were derived from cold plasma jet decomposition and reduction of hydrotalcite-like compounds containing Ni, Co, Mg and Al, and their catalytic performance was investigated with dry reforming of methane. Experimental results showed that the hydrotalcite-like precursors could be completely decomposed and partly reduced by cold plasma jet, and the Ni-contained catalysts exhibited much higher activity than the catalyst without Ni. Especially, the catalyst with Ni/Co ratio of 8/2 achieved not only the highest conversions of 80.3% and 69.3% for CH 4 and CO 2 , respectively, but also the best stability in 100 h testing. The catalysts were characterized by XRD, XPS, TEM and N 2 adsorption techniques, and the results showed that the better performance of the 8Ni2Co bimetallic catalyst was attributed to its higher metal dispersion, smaller metal particle size, as well as the interaction effect between Ni and Co, which were brought by the special catalyst preparation method.

A Novel Reduction Method for Ni/γ-Al2O3 Catalyst by a High Frequency Cold Plasma Jet at Atmospheric Pressure

Abstract The Ni/γ-Al 2 O 3 catalyst was reduced by a high frequency cold plasma jet at atmospheric pressure. The performance of the catalyst for carbon dioxide reforming of methane was investigated. The process of catalyst reduction with plasma was quick and simple and was completed in only 10 min, giving activity and selectivity higher than those of the catalyst prepared by the conventional method. At the CH 4 /CO 2 molar ratio of 4/6 and the reaction temperature of 850°C, the methane conversion and CO 2 conversion reached up to 95.77% and 75.65%, respectively, and a hydrogen selectivity of 100% and a CO selectivity of 94.79% were obtained over the novel catalyst reduced by plasma. The novel catalyst exhibited good stability during a reaction test for 36 h. XRD characterization showed that only a metallic nickel phase and γ-alumina existed in the catalyst reduced by plasma, and the NiAl 2 O 4 phase and other nickel oxides were not detected. The nickel particle size of the catalyst was smaller than that of the conventional catalyst. An enhanced dispersion was achieved with the plasma reduction.

Ni/MgO catalyst prepared using atmospheric high-frequency discharge plasma for CO2 reforming of methane

Abstract A new type of Ni/MgO catalyst was prepared using atmospheric high-frequency discharge cold plasma. The influences of conventional method, plasma method, and plasma plus calcination method on the catalytic activity were studied and the CO 2 reforming of methane was chosen as the probe reaction. The catalysts were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), X-ray photoelectron spectroscopy, and CO 2 temperature-programmed surface reaction techniques. The results suggested that the nickel-based catalyst prepared by plasma plus calcination method possessed a smaller particle size and a higher dispersion of active component, better low-temperature activity and enhanced anti-coking ability. The conversion of CO 2 and CH 4 was 90.70% and 89.37%, respectively, and the reaction lasted for 36 h without obvious deactivation under 101.325 kPa and 750 °C with CO 2 /CH 4 = 1/1.