摘要
采用沉积-沉淀法制备了Pt/Pr6O11催化剂,应用于巴豆醛气相选择性加氢生成巴豆醇的反应。Pt/Pr6O11催化剂经700℃还原后,巴豆醇初始选择性可以达到75%以上。H2-TPR和In situFTIR结果表明,还原后的Pt/Pr6O11催化剂中存在低价态的Pr3+,在巴豆醛加氢过程中能够给Pt提供电子,增加活化C=O键的能力,从而提高生成巴豆醇的选择性。Raman光谱实验结果表明,反应过程中Pt/Pr6O11催化剂表面有积炭产生,而积炭是造成催化剂活性和选择性下降的主要原因。
The selective hydrogenation of crotonaldehyde to crotyl alcohol was studied over Pt/Pr6O11 catalysts prepared by deposition precipitation method.The Pt/Pr6O11 catalysts reduced at 700 ℃ had an initial selectivity of 75% for crotyl alcohol with 20% conversion of crotonaldehyde.The results of H2-TPR and In situ FTIR showed the presence of a large portion of Pr3＋ ions in Pt/Pr6O11 catalysts after H2 reduction pretreatment.Such Pr3＋ ions could provide electrons to the surface of Pt particles,which could induce some special active sites at the interface between Pt particles and Pr6O11 particles.The formed special active sites could preferably adsorb C=O bond and improve the selectivity for crotyl alcohol.The Raman spectra indicated that there were coke depositions during the hydrogenation reaction,which could account for the decrease of activity and selectivity for crotyl alcohol.
出处
《中国稀土学报》
CAS
CSCD
北大核心
2009年第6期756-760,共5页
Journal of the Chinese Society of Rare Earths
