钴的引入对双环戊二烯氢甲酰化担载Rh催化剂的性能影响

以双环戊二烯(DCPD)氢甲酰化反应为探针反应,系统考察了无机氧化物担载的Rh催化剂上引入Co后对性能的影响。实验结果表明:Co的引入不仅可以大幅度的提高DCPD氢甲酰化产物三环癸烷二甲醛(DFTD)的选择性,而且可以加快DFTD的生成速率;相对于Rh催化剂,引入Co之后,DFTD的选择性可以提高20%以上,DFTD的选择性最高可达88.7%。为研究Rh催化剂上引入Co对催化剂活性和目标产物选择性大幅提高的原因,分别对催化剂进行了程序升温还原(TPR)和程序升温脱附(TPD)的表征。TPR的结果显示Co和Rh发生了相互作用,Rh的还原峰明显发生了一定的位移;TPD的结果显示Rh在载体表面的分散性有降低的趋势,表面的Rh活性物种有一定的减少。结合实验数据和表征数据,Rh催化剂上引入Co使催化活性和产物选择性提高的原因可归结为:Co和Rh发生了相互作用;Co的引入虽然造成了表面Rh含量降低,但是形成了高于Rh的活性的新物种,从而导致了催化剂活性和目标产物选择性大幅提高。

Effect of cobalt on properties of Rh based catalysts for the hydroformylation of DCPD

The effects of Co on properties of Rh based catalysts supported on the inorganic oxides were carried out with the dicyclopentadiene （DCPD） hydroformylation as the probe reaction. Co was introduced to the Rh based catalysts supported on the inorganic oxides, the diformyltricyclodecane （DFTD） selectivity and the DFTD formation rate were significantly improved. Compared to Rh catalyst,DFTD selectivity could be increased over 20%, up to 88.7% DFTD selectivity could be achieved, when Co was introduced to the Rh catalysts. In order to probe the catalytic reaction mechanism, the catalysts were characterized by TPR and H2-TPD. The TPR data suggested that interaction occurred among Co,Rh species;H2-TPD data indicated that a lower Rh dispersion occured,and a lower content of Rh species on the surface was observed. In combination with the results and the characterized data, the effect of Co on the properties of Rh based catalysts supported on the inorganic oxides could be summarized as followed：Interaction occurred among Co and Rh species;a new catalytically active component was formed,which had a significantly catalytic activity,thus a higher DFTD selectivity and formation rate were achieved.