Cadmium as a Robust and Novel Promoter over Ni@γ-Al2O3 Catalysts in Dry Methane Reforming

To date, various promoters (noble and non-noble metals)have beenemployed to improve the activity of the nickel-based catalysts indry methane reforming (DMR), an essential and challenging endothermicchemical reaction. In this study, for the first time, we thoroughlyinvestigated the promotional effect of cadmium over Ni@& gamma;-Al2O3 for DMR (CH4/CO2 = 1:1)under four temperatures (600-750 & DEG;C). In this line, severalmonometallic and bimetallic catalysts based on the commercial aluminumoxide anhydrous were synthesized through precipitation-deposition.The synthesized catalysts (Cd/Ni@Al2O3) werecharacterized by utilizing N-2 adsorption-desorption(BET), X-ray diffraction, scanning electron microscopy, inductivelycoupled plasma atomic emission spectroscopy, H-2 temperature-programmedreduction, CO2 temperature-programmed desorption (CO2-TPD), H-2 temperature-programmed desorption (H-2-TPD), thermal gravimetric analysis, and X-ray photoelectronspectroscopy. Based on the obtained results, alloying nickel withcadmium amplified nickel particles' reducibility and significantlyincreased its dispersion (dilution effect) and basicity of the preparedcatalysts. These features resulted in the high activity and stabilityof Cd(5%)/Ni(15%)@Al2O3 in DMR reaction under600-750 & DEG;C. Remarkably, this catalytic process showedhigh resistance toward coke formation (graphite carbon about 10%)and excellent activity after a 30 h catalytic run at 700 & DEG;C.