甲烷部分氧化制合成气Ⅳ．镍铜催化剂的反应性能及影响因素的考察

Methane Partial Oxidation to Carbon Monoxide and Hydrogen Ⅳ. The Activity of Ni Cu Catalysts and the Search of Effect Factors

对镍铜甲烷部分氧化催化剂的制备化学研究表明，在Ａｌ２Ｏ３、ＳｉＯ２、ＭｇＯ、ＴｉＯ２、Ｙ型分子筛等载体中，具有较好氢溢流功能的Ａｌ２Ｏ３所担载的镍铜催化剂，有最佳的反应性能，载体的产物溢流功能对反应中合成气的生成是有利的．对于ＮｉＯ－ＣｕＯ－Ａｌ２Ｏ３催化剂，组分Ｃｕ的最佳含量是Ｃｕ／Ａｌ＝０．２／４（原子比），Ｎｉ／Ａｌ（原子比）在１／４－１．５／４范围内催化剂均保持最佳的反应性能，此时，甲烷转化率为９８．１％，对ＣＯ、Ｈ２的选择性分别达９７％、１００％．制备方法对催化性能影响的结果显示，以（ＮＨ４）２ＣＯ３为沉淀剂的共沉淀法，是制备ＮｉＯ－ＣｕＯ－Ａｌ２Ｏ３催化剂的最佳方法．ＮｉＯ－ＣｕＯ－Ａｌ２Ｏ３催化剂的甲烷部分氧化性能在４００－５００℃间有一突跃，并在７００℃时达到最佳值；过高的反应气空速对ＣＯ。

Among the Ni Cu catalysts supported on Al 2O 3, SiO 2, MgO, TiO 2 and Y zeolite respectively, NiO CuO Al 2O 3 has the best catalytic activity for partial oxidation of methane to H 2 and CO, because Al 2O 3 has the best hydrogen spillover function useful for syngas production. The best composition of Ni Cu Al catalysts is Ni∶Cu∶Al=1 1.5∶0.2∶4(atom ratio), over this catalyst, 98.1% conversion to CH 4 and 97%, 100% selectivities to CO、 H 2 have been achieved. The NiO CuO Al 2O 3 catalyst prepared by coprecipitation using (NH 4) 2CO 3 as the precipitating agent shows the best catalytic activity. As the reaction temperature increases from 400℃ to 800℃, the catalytic activity of NiO CuO Al 2O 3 increases greatly and has the optimum value at 700℃. Extremely high space velocity is unfavorable for the syngas selectivity.