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研究了Al2 O3 担载的硫化CoMo催化剂上NO被H2 还原的规律 ,并考察了不同Mo含量的CoMo/Al2 O3 催化剂、单一的Mo/Al2 O3 和Co/Al2 O3 催化剂 ,以及原料气中H2 /NO比对反应活性和选择性的影响 .结果表明 ,硫化的 5 1%Co 15 2 %Mo/Al2 O3 催化剂具有最高的催化活性和选择性 ,在 2 0 0℃以下时反应产物为N2 O ,在 35 0℃以上时则完全转化为N2 .进一步增加Mo含量引起在 35 0～ 4 5 0℃间N2 选择性轻微下降 .提高原料气中的H2 含量可明显提高反应活性和N2 选择性 ,但当n(H2 ) /n(NO) >3后反应性能不再变化 .催化剂具有较高的稳定性 ,反应产物中始终未观察到有H2 S或SO2 产生 ,即反应未引起催化剂中的晶格S流失 .这说明H2 的存在抑制了NO对硫化物表面的氧化所导致的催化剂失活
The reduction of NO by H2 on Al2 O3 -supported CoMo catalyst was investigated. The effects of different Mo content on CoMo / Al2 O3 catalyst, single Mo / Al2 O3 and Co / Al2 O3 catalysts and H2 / NO ratio on the reactivity and selectivity.The results show that the sulfided 5 1% Co 15 2% Mo / Al 2 O 3 catalyst has the highest catalytic activity and selectivity, and when the temperature is below 200 ℃, the reaction product is N 2 O, When the temperature is above 35 0 C, N2 is completely converted into N2, further increase of Mo content causes a slight decrease of N2 selectivity at 35 0-4 500 ° C. Increasing H2 content in the feed gas can obviously improve the reactivity and N2 selectivity, When n (H2) / n (NO)> 3, the reaction performance did not change any more.The catalyst had high stability and no H2S or SO2 was observed in the reaction product, that is, the reaction did not cause the lattice in the catalyst S. This suggests that the presence of H2 inhibits the catalyst deactivation caused by the oxidation of NO to the sulfide surface