反应气中水对钼基甲烷化催化剂性能的影响

在反应温度550 ℃、空速5 500 h^-1、H₂S体积分数1.2%下对所研制的钼基催化剂进行了耐硫甲烷化活性评价，考察了反应气中添加H₂O对Mo基催化剂耐硫甲烷化活性的影响。结果表明，反应气中添加水对Al₂O₃负载的Mo基催化剂可造成不可逆失活，而添加Co助剂及采用铈铝复合载体的催化剂其稳定性、活性得到了改善和提高。Co的添加能保护Mo基催化剂上的活性组分MoS₂，抑制添加水导致的不可逆失活。当反应气中加入水时，催化剂上主要发生水汽变换反应，且随着水含量升高，水汽变换反应速率增大，会严重影响甲烷化反应的进行。此外，随着水含量的增加，其对催化剂的耐硫甲烷化活性和稳定性的影响程度变大。

Influence of water on the methanation performance of Mo-based catalyst

The effects of H₂O on the performance of the sulfur-resistant Mo-based methanation catalysts were investigated by adding vapor into the reactant gas at the reaction conditions of 550℃, 5 500 h^-1, 1.2% of H₂S concentration. The results indicate that water caused irreversible deactivation of Mo-based catalyst supported on Al₂O₃, while additive Co and cerium-aluminum composite carrier can enhance the activity and improve the stability of the Mo-based catalyst for methanation of syngas. The promoter Co protects the active phase MoS₂ of Mo-based catalyst, inhibits the irreversible deactivation caused by the addition of water. When the water content in reactant gas is increased, the water gas shift reaction increases and becomes the main reaction on catalysts, and the increase of water leads to further decrease of the catalyst activity and stability.