酸活化蒙脱土在二甲醚水蒸气重整制氢中的应用

Acid activation of montmorillonite and its application for production of hydrogen via steam reforming of dimethyl ether

采用硝酸溶液在不同温度和时间下对钠基蒙脱土进行处理,制备了一系列酸活化蒙脱土(Acid-MMT),并以其为固体酸与商品化的Cu/ZnO/Al_(2)O_(3)物理混合组成双功能催化剂用于二甲醚水蒸气重整(SRD)反应。结果表明,与钠基蒙脱土相比,酸活化蒙脱土的结构、织构及酸性均发生了明显的变化,且变化的程度与酸处理条件密切相关。酸活化蒙脱土的结构和酸性明显影响双功能催化剂的SRD反应性能。其中,在80℃处理12 h的酸活化蒙脱土(Acid-MMT-80/12)与Cu/ZnO/Al_(2)O_(3)组成双功能催化剂表现出较好的SRD性能,在p=0.1 MPa,t=350℃,GHSV=3000 h^(−1)的反应条件下,二甲醚转化率和氢收率分别达到了97%和94%,且在反应10 h内基本保持不变,表现出了较好的稳定性。

A series of acid-activated montmorillonites(Acid-MMTs)were prepared via Na-montmorillonite treated with nitric acid solution at different treatment temperature and time.And the Acid-MMTs used as solid acid were physically mixed with commercial Cu/ZnO/Al_(2)O_(3) to obtain bifunctional catalysts for steam reforming of dimethyl ether(SRD)reaction.The results showed that the structure,texture and acidity of Acid-MMTs were significantly changed compared with Na-MMT,which was dependent on the acid treatment conditions.The structure and acidity of Acid-MMTs obviously affected the SRD performance over bifunctional catalyst.The bifunctional catalyst composed of the Na-MMT activated in 20%nitric acid solution at 80℃for 12 h(Acid-MMT-80/12)and Cu/ZnO/Al_(2)O_(3) exhibited the best SRD performance,with the dimethyl ether conversion and H2 yield reaching 97%and 94%under the conditions of p=0.1 MPa,t=350℃,GHSV=3000 h^(−1),respectively,and DME conversion and H2 yield remained basically constant in 10 h,indicating that the catalyst had better stability.