助剂对钼基催化剂耐硫甲烷化性能的影响

摘要

Unsupported Mo-based catalysts were prepared by thermal decomposition method using ammonium heptamolybdate (AHM) and sulfur powder as raw materials, and the effect of three additives on the performances of the Mo-based catalysts for sulfur-resistant methanation was studied. The results indicated that Co additive reduced the catalytic activity, and both of Zr and Al2O3 could not only keep the catalytic activity but also improve the stability. The investigation on effect of Al2O3 content on the stability of MoS2 catalysts showed that the most stable catalyst was that prepared by a Al2O3/AMH mass ratio of 0.2, and BET, XRD and TEM results revealed that the major reasons for increasing stability were that the addition of appropriate Al2O3 improved Mo dispersion and decreased sintering of MoS2.%以仲钼酸铵（AHM）和硫粉为原料，利用热分解法制备了非负载型钼基催化剂，并考察了添加三种助剂对钼基催化剂耐硫甲烷化性能的影响。结果表明，添加Co助剂抑制了甲烷化反应活性，添加Zr、Al助剂既维持了催化剂原有活性又提高了催化剂的稳定性。进一步考察了不同Al2O3添加量对钼基催化剂反应性能的影响，发现m(Al2O3)/m(AHM)为0.2时所制备的钼基催化剂的稳定性最好。采用BET、XRD、TEM 技术对催化剂进行了表征，发现添加Al2O3可以提高MoS2的分散度，防止MoS2的聚集，这是导致催化剂稳定性提高的主要原因。