Wasim Ullah Khan

Stabilities of zeolite-supported Ni catalysts for dry reforming of methane

Ni/γ-Al2O3, Ni/Y-zeolite, and Ni/H-ZSM-5 catalysts were prepared using the incipient wetness impregnation method. Their catalytic performance in dry reforming of methane was studied. The fresh and used catalysts and deposited carbon were characterized using H2 temperature-programmed reduction, temperature-programmed oxidation, N2 adsorption-desorption, X-ray diffraction, and thermogravimetric analysis. The H-ZSM-5-supported Ni catalyst proved to be more stable than the other two catalysts, as it had the lowest carbon deposition.

Hydrogen production by catalytic methane decomposition over Ni, Co, and Ni-Co/Al2O3 catalyst

ABSTRACT Hydrogen is a chief source of energy. Catalytic decomposition produces hydrogen and carbon. In this work, x%M/Al2O3 (where M is Ni, Co and combined Ni-Co, and x is 10%, 15%, and 30%) has been successfully employed as a catalyst. The effect of activation temperature and active metal type and loading on catalyst perfomance was investigated. The catalysts were characterized with BET, XRD, TPO, TPR, TEM, XPS, and Raman. The results displayed that the 30%Co/Al2O3 catalyst activated at 500°C provided the greatest catalytic performance toward methane conversion. 30%Co/Al2O3 catalyst activated at 500°C formed amorphous carbon.

Methane decomposition over Fe supported catalysts for hydrogen and nano carbon yield

Abstract Production of hydrogen, being an environmentally friendly energy source, has gained a lot of attention in the recent years. In this article, iron-based catalysts, with different active metal loadings, supported over magnesia and titania are investigated for hydrogen production via catalytic decomposition of methane. The catalytic activity and stability results revealed that magnesia supported catalysts performed better than titania supported catalysts. Hydrogen reduction temperature of 500°C was obtained suitable for catalyst activation. For magnesia supported catalysts, only higher loadings i.e., 30% and 40% Fe-Mg catalysts showed reasonable activity, while all titania supported catalysts presented less activity as well as deactivation. Among all the catalysts, 30% Fe/MgO catalyst displayed better activity. The formation of carbon nanofibers was evidenced from morphological analysis. FESEM and TEM images showed the generation of nonuniform carbon nanofibers with broader diameter. The catalysts were characterized using different techniques such as BET, H2-TPR, O2-TPO, XRD, TGA, FESEM and TEM.

Reforming of Methane by CO2 over Bimetallic Ni-Mn/γ-Al2O3 Catalyst

γ-Al2O3 supported Ni-Mn bimetallic catalysts for CO2 reforming of methane were prepared by impregnation method. The reforming reactions were conducted at 500–700 °C and atmospheric pressure using CO2/CH4/N2 with feed ratio of 17/17/2, at total flow rate of 36 mL/min. The catalytic performance was assessed through CH4 and CO2 conversions, synthesis gas ratio (H2/CO) and long term stability. Catalytic activity and stability tests revealed that addition of Mn improved catalytic performance and led to higher stability of bimetallic catalysts which presented better coke suppression than monometallic catalyst. In this work, the optimum loading of Mn which exhibited the most stable performance and least coke deposition was 0.5wt%. The fresh and spent catalysts were characterized by various techniques such as Brunauer-Emmett-Teller, the temperature programmed desorption CO2-TPD, thermogravimetric analysis, X-ray diffraction, scanning electron microscope, EDX, and infrared spectroscopy.

Catalytic Decomposition of Methane over La2O3 Supported Mono- and Bimetallic Catalysts

Catalytic decomposition of methane was investigated over nickel and cobalt based mono-and bimetallic catalysts for the production of hydrogen and filamentous carbon. Catalysts with different Ni to Co ratios supported on La2O3 were prepared by co-precipitation method. The activity test and characterization results revealed that the catalyst containing 15wt% Ni and 10wt% Co over La2O3 support presented relatively better catalytic performance among all the tested catalyst. The catalysts were characterized by BET, TGA and temperature programmed reduction (TPR).