一步合成二甲醚催化剂烧结失活和原位再生的研究  

Sintering deactivation and regeneration of hybrid catalysts in one-step synthesis of dimethyl ether from syngas

作　　者：栾友顺[1] 徐恒泳[1] 于春英[1] 李文钊[1] 侯守福[1] 

机构地区：[1]中国科学院大连化学物理研究所,辽宁大连116023

出　　处：《燃料化学学报》2008年第1期70-73,共4页Journal of Fuel Chemistry and Technology

摘　　要：采用共沉淀沉积法制备了CuOZnOAl2O3/γ-Al2O3-HZSM-5复合催化剂,考察了其对CO加氢直接合成二甲醚的催化性能,研究了催化剂的失活和再生,并用H2-TPR、XRD、TPO、N2O化学吸附等表征方法对反应前后和再生后催化剂的物化性质进行了表征。结果表明,一步合成二甲醚催化剂的失活主要是由于活性位Cu晶粒的烧结长大;反应温度和原料气的组成是影响催化剂失活的因素,在低于220℃下,以N2/H2/CO/CO2为原料气会显著降低催化剂的失活速率。研究使用的氧化还原循环的再生方法能够使Cu晶粒发生再分散,并使失活的催化剂恢复了75%以上的活性。One-step synthesis of dimethyl ether （DME） from H2/CO was studied in a fixed bed reactor over hybrid catalyst CuOZnOAl2O3/γ-Al2O3-HZSM-5. The physical-chemical properties of the catalysts were also studied by means of HE-TPR, XRD, TPO and N2O chemi-sorption. The results showed that in the process of catalyst deactivation, surface area of metallic Cu decreased greatly, but kept nearly constant TOF and selectivity to DME. Temperature-programmed oxidation （TPO） of the deactivated catalysts did not show significant O2 consumption, indicating that the deactivation was mainly caused by the sintering and conglomeration of Cu particles rather than carbon deposition or acidity loss. It was found that lower temperature, and N2/H2/CO/CO2 as feed gas could inhibit sintering deactivation. According to the experiment of the catalyst regenerated by means of redox cycle, Cu crystalline was re-dispersed and more than 75 % activity was restored.

关 键 词：烧结失活 再生 铜基催化剂 二甲醚 合成气 

分 类 号：O643[理学—物理化学]