添加碱金属对甲烷与空气制合成气催化剂性能的影响(英文)

考察了添加在镍基催化剂中的碱金属助剂对甲烷与空气制合成气的催化反应性能的影响。并用ＴＰＯ、ＴＰＲ、ＣＯ_２程序升温脱附（ＴＰＤ）、ＸＰＳ及ＣＯ脉冲色谱对催化剂进行了表征。实验结果表明，碱金属助剂对降低催化剂结炭有一定作用；催化剂抗积炭顺序为； Ｎｉ－Ｋ２Ｏ／ＣａＯ／Ａｌ２Ｏ３＞Ｎｉ－Ｌｉ２Ｏ／ＣａＯ－Ａｌ２Ｏ３＞Ｎｉ－Ｎａ２Ｏ／ＣａＯ－Ａｌ２Ｏ３＞Ｎｉ／ＣａＯ／Ａｌ２Ｏ３。在实验中，我们发现碱金属的添加使催化剂的Ｎｉ晶粒变大和吸附ＣＯ_２的能力增强，结合能发生不同程度的变化。这些实验结果从不同方面解释了碱金属助剂对催化剂活性和抗积炭性的影响。实验结果表明Ｎｉ－Ｌｉ２Ｏ／ＣａＯ－Ａｌ２Ｏ３具有较好的活性和抗积炭性。

EFFECT OF ALKALI METAL PROMOTER ON THE PROPERTIES OF Ni/CaO-Al2O3 CATALYST FOR REACTION OF METHANE WITH AIR

The influence of alkali metal promoter in Ni-based catalyst for catalytic oxidation of methane with air to syngas was investigated by using TPO, CO_2-TPD, XPS and CO pulse chromatograph. The experimental results showed that the alkali metal promoter is effective in the suppression of carbon deposition on catalyst. The abilities of resistance to carbon deposition are ordered as below: Ni-K2O/CaO-Al2O3>Ni-Li2O/CaO-Al2O3>Ni-Na2O/CaO- Al2O3>Ni/CaO-A12O3. And, the catalyst Ni-Li2O/CaO-A12O3 has higher activity and selectivity as well. It was found that the Ni crystal sizes in catalyst were enlarged, the abilities of CO_2 adsorption were found to be strengthened, and the binding energies of Ni 2p3/2 were changed as the result of the addition of various alkali metal promoters.