硫化NiW/Al_2O_3催化剂上H_2同时催化还原SO_2和NOⅡ.SO_2和NO的同时还原  

Simultaneous Reduction of SO_2 and NO by H_2 over Sulfided NiW/Al_2O_3 Catalyst Ⅱ.Simultaneous Reduction of SO_2 and NO

作　　者：朱鹏[1] 李雪辉[1] 徐建昌[1] 黄苑[1] 王乐夫[1] 

机构地区：[1]华南理工大学化工与能源学院广东省绿色化学产品技术重点实验室,广东广州510640

出　　处：《催化学报》2005年第10期905-910,共6页

基　　金：国家自然科学基金(20076017;20476032);广东省自然科学基金(030951);广东省科技攻关(2KB06601S)资助项目

摘　　要：对硫化NiW/Al2O3催化剂上H2同时还原SO2和NO反应进行了研究,探讨了温度、空速、H2配比以及Ni负载量对反应的影响.结果表明,催化剂的活性随反应温度的升高而增加,550℃时,SO2和NO在15%Ni-10%W/Al2O3上的转化率达100%,单质硫的产率达90%以上;增加空速对NO转化率和单质硫的选择性影响不大,但SO2转化率及单质硫产率明显下降;提高n(H2)/n(SO2+NO)的比值可显著提高SO2转化率,但单质硫选择性明显下降,其比值为2.0时单质硫产率最大,随后随H2浓度的增加而迅速下降,NO转化率几乎不受H2配比的影响;增加催化剂的Ni含量可明显提高各反应物的转化率及单质硫的选择性和产率;预硫化过程对催化剂性能有很大影响,是获得高活性催化剂的必要条件.催化剂稳定性测试及XRD结果表明,催化剂不会因为晶格硫的大量流失而失活.最后,提出了H2同时还原SO2和NO反应的机理.The simultaneous reduction of SO2 and NO by H2 was carried out over sulfided NiW/Al2O3 catalyst, and the influence of temperature, space velocity, H2 ratio and Ni loading on the reaction was investigated. The results showed that the activity of the catalyst increased with increasing temperature, both SO2 and NO conversion could reach 100 % and the yield of sulfur was over 90 % at 550 ℃ over 15 % Ni-10 % W/Al2O3. The increase of space velocity had less influence on NO conversion and sulfur selectivity, while SO2 conversion and sulfur yield decreased remarkably. With the increase in n （H2）/n （SO2 ＋ NO）, SO2 conversion increased while sulfur selectivity decreased greatly. And the sulfur yield was the highest when n（H2）/n（SO2 ＋ NO）=2.0. NO conversion was hardly influenced by H2 concentration in the feed. Higher conversion of NO and SO2, in addition to higher selectivity and yield of sulfur could be obtained over the catalyst with higher Ni loading. The process of presulfidation influenced the performance of the catalyst greatly and it was necessary for high catalytic activity. The stability test and XRD patterns of the catalyst proved that no deactivation took place with the serious lattice sulfur loss. Finally, the reaction mechanism of the simultaneous catalytic reduction was assumed.

关 键 词：镍 钨 氧化铝 氢气 催化还原 二氧化硫 一氧化氮 废气处理 

分 类 号：O643.32[理学—物理化学]