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The Ni catalysts supported on γ-Al2O3 were synthesized by an impregnation method.Their catalytic performance in methane dry reforming was investigated.The reforming reactions were carried out in a microreactor using a CO2:CH4 feed ratio of 1:1,a F/W = 2640 ml/(h·g),reaction temperatures between 500-850 ?C,and at atmospheric pressure.The influence of Ca,Ce,and Zr promoters on catalyst stability,coke deposition,and the H2/CO ratio were also studied.Effluents were analyzed using an online gas chromatograph equipped with a thermal conductivity detector.The spent and fresh catalysts were characterized by scanning electron microscopy and thermogravimetric analysis.It was found that 3%Ni/γ-Al2O3 promoted with 0.15% Ce and 0.05% Ca gave the best performance and resulted in less coke formation.The highest CH4 and CO2 conversion activities were found to be 94.1% and 98.3% at 850 ?C,respectively.Stability tests were carried out for 130 h and this provided a H2 yield of 91%.Moreover,the amount of formed carbon was negligible and did not increase to more than 1.5 wt%.
The Ni catalysts were synthesized on an impregnation method. The catalytic performance in methane dry reforming was investigated. The reforming reactions were carried out in a microreactor using a CO2: CH4 feed ratio of 1: 1, a F / W = 2640 ml / (h · g), reaction temperatures between 500-850 ° C, and at atmospheric pressure. The influence of Ca, Ce, and Zr promoters on catalyst stability, coke deposition, and the H2 / CO ratio were also studied . Effluents were analyzed using an online gas chromatograph equipped with a thermal conductivity detector. Spent and fresh catalysts were characterized by scanning electron microscopy and thermogravimetric analysis. It was found that 3% Ni / γ-Al2O3 was promoted with 0.15% Ce and 0.05% Ca gave the best performance and resulted in less coke formation. The highest CH4 and CO2 conversion activities were found to be 94.1% and 98.3% at 850? C, respectively.Stability tests were carried out for 130 h and this provided a H2 yield of 91% .Moreover, the amount of formed carbon was negligible and did not increase to more than 1.5 wt%.