Co-Ni/MgO催化剂上低温甲烷二氧化碳干重整研究

Dry Reforming of Low Temperature Methane CO_(2)Over Co-Ni/MgO Catalysts

采用溶胶凝胶法制备Ni/MgO和Co-Ni/MgO催化剂,考察了催化剂在甲烷二氧化碳低温干重整反应中的性能。结果表明1%Co-10%Ni/Mg O催化剂拥有较高的CH_(4)、CO_(2)转化率以及最高的H_(2)/CO,且在450℃下反应20 h后该催化剂的CH_(4)、CO_(2)转化率以及H_(2)/CO仍高于Ni/Mg O催化剂,且积碳量比Ni/MgO催化剂少4.3%。通过XRD、H_(2)-TPR、TEM、SEM、TG、RAMAN等表征分析发现适量Co的添加有利于提升催化剂表面活性组分的分散度和粒径,减少催化剂颗粒的团簇,且能抑制积碳的形成。通过对干重整反应过程中反应物表观活化能的计算,发现适量Co的添加能降低反应物的表观活化能,有利于提升Ni/MgO催化剂的低温甲烷干重整反应性能。

The Ni/MgO and Co-Ni/MgO catalysts were prepared by sol-gel method,and the per-formance of the catalysts in the low-temperature dry reforming reaction of methane CO_(2)was inves-tigated.The results showed that the 1%Co-10%Ni/MgO catalysts possessed higher CH_(4)and CO_(2)conversions and the highest H_(2)/CO_(2)and the CH_(4)and CO_(2)conversions and H_(2)/CO of the catalysts were still higher than those of the Ni/MgO catalysts after 20 h of reaction at 450°C,and the carbon accumulation was 4.3%less than that of the Ni/MgO catalysts.The XRD,H_(2)-TPR,TEM,SEM,TG,and RAMAN characterization revealed that the addition of Co was beneficial to enhance the dispersion and particle size of the active components on the catalyst surface,reduce the clustering of catalyst particles,and inhibit the formation of carbon accumulation.By calculating the apparent activation energy of the reactants during the dry reforming reaction,it was found that the addition of moderate amount of Co could reduce the apparent activation energy of the reactants and improve the performance of Ni/MgO catalysts for low-temperature methane dry reforming reaction.