焙烧温度对Fe-Mn催化剂结构和合成低碳烯烃性能的影响

在不同的焙烧温度下制备了Fe-Mn沉淀型催化剂,以CO加氢合成低碳烯烃为模型反应在固定床反应器上对催化剂的反应性能进行了考察,并借助X射线物相分析、N2物理吸附、程序升温还原等表征手段对催化剂进行了表征。实验结果表明,随着焙烧温度的升高,催化剂中α-Fe2O3晶粒增大,催化剂比表面积减小。在CO加氢反应中,焙烧温度的升高明显地提高了催化剂的运行稳定性,降低了CH4的选择性,促进了链增长。450℃条件下焙烧的催化剂烯烃选择性最高,有较高的低碳烯烃收率。

Effect of calcination temperature on structure and catalytic performance of Fe-Mn catalysts for synthesis of light olefins from syngas

A group of co-precipitated Fe-Mn catalysts were prepared using different calcinaton temperatures and characterized by XRD,BET and H2-TPR techniques,while their catalytic properties in the synthesis of light olefins via carbon monoxide hydrogenation were investigated in a fixed-bed reactor.The results showed that the increase of calcination temperature increased the crystallite size of α-Fe2O3 and decreased the specific surface area of the catalysts.Calcining the catalysts at higher temperature could improve the activity stability of the catalysts,decrease the selectivity to methane,and promote the chain propagation.The catalyst calcined at 450℃ showed the highest selectivity and good yield for light olefins.