Mg、Ce修饰纳米Al_2O_3负载Ni催化剂对CH_4、CO_2重整反应制合成气的影响

考察了助剂Mg、Ce修饰的纳米A l2O3负载N i催化剂对CH4、CO2重整反应制合成气的反应性能影响,采用正交实验筛选催化剂。结果表明,N i含量在9%~13%时,催化剂表现出较好的活性;随Mg含量的增加,反应活性基本呈下降趋势,说明Mg降低了催化剂体系的反应性能;Ce的加入总体上提高了反应活性,但是当Ce含量为3%时,反应活性最好;从不经预还原实验和低温点反应实验推断出,CH4和CO2重整反应中关键反应步骤是CH4的裂解;助剂Ce有利于提高催化剂的稳定性,而Mg却会使催化剂的稳定性下降很快。

Effect of adding Mg and Ce in CO2 reforming of CH4 to syngas over Ni/nano-Al2O3 catalysts

The effects of the oxides lysts were investigated. Orthogonal of Mg and Ce on the CO2 reforming of CH4 over Ni/nano-Al2O3 cata- experimental methodology was applied to select the most suitable catalysts. The results showed that Ni/nano-Al2O3 catalysts exhibit high reactivity when the Ni content is 9% - 13%. As the content of Mg increasing,the reactivity of catalysts is decreased,that is to say, Mg is not suitable for this reaction. On the contrary, the reactivity of catalysts can be improved by Ce on the whole, especially when the Ce content is 3%. It is certificated that the decomposition of CH4 is the key step of reforming reaction from unpretreatment and lower temperature experiments. The stability of catalysts can be improved by Ce but not Mg.