摘要
利用普通浸渍法、共沉淀法和溶剂化金属原子浸渍法制备了一系列Cu Cr/γ Al2 O3催化剂 ,并用X射线衍射、扫描电镜、透射电镜和X射线光电子能谱等技术对这些催化剂进行了表征 .结果表明 ,不同方法制备的催化剂的金属粒度的顺序为溶剂化金属原子浸渍法 <共沉淀法 <普通浸渍法 ;金属还原程度的顺序为溶剂化金属原子浸渍法 >普通浸渍法≈共沉淀法 .糠醛加氢反应实验结果表明 ,催化活性顺序为溶剂化金属原子浸渍法 >普通浸渍法 >共沉淀法 ;生成 2 甲基呋喃选择性顺序为共沉淀法 >普通浸渍法 >
Conventional impregnation (CI), coprecipitation (CP) and solvated metal atom impregnation (SMAI) were used to prepare a series of Cu-Cr/γ-Al_2O_3 catalyst samples. The samples prepared by the three different methods are termed CI catalyst, CP catalyst and SMAI catalyst, respectively. These catalyst samples were characterized by XRD, SEM, TEM and XPS techniques. The results showed that the metallic particle size of SMAI catalyst lay the smallest ( d=9.7 nm), the metallic particle size of CI catalyst was the largest( d=41.2 nm) and the metallic particle size of CP catalyst lay between them ( d=24.5 nm). The particles of SMAI catalyst were finer and more uniformly distributed than those of CI catalyst and CP catalyst. Both Cu and Cr on SMAI catalyst existed in zero-valence state and partially in +1-valence state (Cu_2O), and in +3-valence state (Cr_2O_3). The activity of SMAI catalyst was the highest and the conversion of furfural was 100% (TON=3.02), while the conversion of furfural on CI catalyst and CP catalyst was 85% (TON=2.57) and 82% (TON=2.48), respectively. The selectivity for 2-methylfuran on CP catalyst was 92.5%, while that on SMAI catalyst was 88.2%, and that on CI catalyst was 91.3%. The zero-valence copper may be the catalytic active center for hydrogenation of furfural to 2-methylfuran.
出处
《催化学报》
SCIE
EI
CAS
CSCD
北大核心
2003年第1期27-31,共5页
