还原温度对Mo基催化剂物相及其加氢脱氧性能的影响  

Effect of reduction temperature on Mo-based catalyst phase and its activity in hydrodeoxygenation reaction

作　　者：梁俊梅[1] 陈宇[2] 丁冉冉[2] 孟永强[1] 王要武[2] 杨明德[2] 吴玉龙[2] 

机构地区：[1]河北科技大学材料科学与工程学院,河北石家庄050018 [2]清华大学核能与新能源技术研究院,北京100084

出　　处：《化工进展》2016年第5期1452-1459,共8页Chemical Industry and Engineering Progress

基　　金：国家自然科学基金(21376140;21576155);广东省科技计划(2015B020215004)项目

摘　　要：以碳纳米管(CNTs)为载体,通过控制催化剂合成的还原温度制备了一系列负载型Mo基催化剂。采用XRD、TEM、N2物理吸附、XPS以及NH_3/H_2-TPD等技术对催化剂进行了表征,并研究了Mo基催化剂对硬脂酸催化加氢脱氧性能的影响。结果表明:随着还原温度的升高,催化剂表面的Mo物种逐渐被还原,还原过程为:Mo O_3→Mo O_2→Mo→Mo_2C。还原温度为450℃和550℃时,催化剂的活性相为Mo O_2;还原温度为600℃时,催化剂的活性相为Mo O_2/Mo/β-Mo_2C的混合相;还原温度为650℃和700℃时,催化剂的活性相全部转化为β-Mo_2C。与活性相Mo O_2催化剂相比,β-Mo_2C催化剂具有更高的加氢脱氧活性。此外,还原温度为600℃的Mo O_2/Mo/β-Mo_2C混合相催化剂因具有较大的比表面积、较多的酸中心数量和较强的H_2吸附能力,使得该催化剂在硬脂酸加氢脱氧反应中表现出最优越的催化活性。A series of Mo-based catalysts supported over CNTs were successfully prepared by controlling the reduction temperature during the catalyst synthesis. The properties of the obtained catalysts were systematically characterized by XRD,TEM,N2 adsorption,XPS and NH_3/H_2-TPD techniques,and the catalytic reactivity for the hydrodeoxygenation of stearic acid was evaluated. The results showed that Mo species on the surface of catalysts were reduced with the increase of reduction temperature,and the reduction process was as followed： Mo O_3→Mo O_2→Mo→Mo_2C. The active phase was Mo O_2 when reduction temperature was below 550℃. Further elevating the reduction temperature to 600℃,we found a mixed phase of Mo O_2/Mo/β-Mo_2 C existed. β-Mo_2 C was the main active phase when reduction temperature was over 650 ℃, and it exhibited higher activity of hydrodeoxygenation than the active phase of Mo O_2. In addition,the Mo O_2/Mo/β-Mo_2 C mixed phase catalyst at 600℃ showed the highest catalytic reactivity in hydrodeoxygenation of stearic acid due to its large specific surface area,more acid sites and stronger H_2 adsorption ability.

关 键 词：Mo基催化剂 还原 加氢 活性 

分 类 号：TK6[动力工程及工程热物理—生物能]