双金属杂原子分子筛CrCoBEA的合成、波谱及催化性能研究

Studies on the Synthesis, Spectroscopy and Catalytic Properties of CrCoBEA Metallosilicate

采用水热晶化法首次合成出BEA结构含铬、钴双金属杂原子分子筛CrCoBEA ,对晶化时间、晶化温度、成胶配比等合成条件进行了优化研究 .采用XRD ,FTIR ,UV VisDRS ,ESR及催化反应等方法测试其物相、波谱性质和催化性能 .结果表明 ,物质的量比为TEOS∶0 0 1 7[Cr(acac) 3]∶0 0 1 7[Co(acac) 3]∶(0 5 8 0 6 4)TEAOH∶0 0 1Al(NO3) 3∶(1 6 2 0 )H2 O的成胶体系在 40 842 8K静态晶化 90 1 5 0h ,可合成出结晶度高且晶相单一的CrCoBEA分子筛 .铬、钴在晶化过程中进入分子筛骨架 ,并以多种化学状态高度分散于分子筛上 .所合成的杂原子分子筛对环己烯氧化和NO分解反应有较好的催化活性 .环己烯氧化反应活性和NO分解反应的活性顺序分别为 :CrCoBEA >CoBEA >CrBEA和CrBEA >CrCoBEA >CoBEA .

Metallosilicates with BEA structure simultaneously containing chromium and cobalt have been hydrothermally synthesized for the first time under static conditions. By varying temperature, time as well as concentration of the starting materials, the optimal conditions for the synthesis of CrCoBEA molecular sieve were deduced. The crystallinity, spectroscopic property and catalytic activity of CrCoBEA were evaluated by means of XRD, FTIR, UV Vis DRS, ESR and catalytic tests, respectively. The result reveals that crystallization with gel molar composition of TEOS∶0.017[Cr(acac) 3]∶0.017[Co(acac) 3]∶(0.58~0.64)TEAOH∶0.01Al(NO 3) 3∶(16~20)H 2O at 408~428 K after 90~150 h gave a high crystallinity, uni phased CrCoBEA molecular sieve. Both chromium and cobalt ions incorporated into the framework during crystallization were highly dispersed with multiple chemical status. The CrCoBEA molecular sieve exhibited promising catalytic activities in the selective oxidation of cyclohaxene with dilute H 2O 2 and the decomposition of NO. The order of activity for selective oxidation of cyclohexene and decomposition of NO were CrCoBEA>CoBEA>CrBEA and CrBEA>CrCoBEA>CoBEA, respectively. [WT5HZ]