닫기
18.97.9.171
18.97.9.171
close menu
SCOPUS
레늄카보닐에 의한 고활성 메타세시스 촉매제조 및 그의 촉매작용
Preparation of Highly Active Metathesis Catalyst from Rhenium Carbonyl and its Catalysis
안호근 ( Ho Geun Ahn )
공업화학 vol. 9 iss. 1 115-120(6pages)
UCI I410-ECN-0102-2009-570-007339127

메타세시스에 높은 활성을 나타내는 고분산 레늄촉매를 제조하기 위한 레늡카보닐 침착의 표면화학 및 활성점 생성에 관하여 연구하였다. 알루미나는 773K(PDA)와 1223K(DA)에서 각각 처리하여 담체로 사용하였고, 메타세시스 활성은 순수한 프로펜을 사용하여 상압하의 298K에서 조사하였다. PDA상의 레늄 산화가는 상당히 높았으나, DA에서는 저산화가의 레늄으로 담지되어 있었다. 제조한 Re/DA촉매를 고온에서 열분해시킨 다음 저온에서 산소로 처리하면 메타세시스 활성이 나타났고, 그 활성은 극히 낮은 담지율에서도 Re/PDA이나 통상의 Re₂O_7/Al₂O₃촉매에 비해 높은 활성을 보여, 레늄 카보닐을 출발물질로 하고 DA를 사용하는 것이 효과적이었다. 열분해하여 얻은 Re/DA촉매상의 레늄이온은 알루미나의 산소원자 2개와 결합하여 2가를 가지고, 산소처리에 의하여 4가만큼 증가한 6가의 레늄이온이 되며, 메타세시스는 그 6가이온에 의해 생성된 카르벤착체를 통하여 진행됨을 알았다.

The surface chemistry of Re₂(CO)_10 deposition for preparing highly dispersed rhenium catalysts and the formation of active site for the metathesis were studied. Alumina as support was treated at 1223K(DA) and 773K(PDA), respectively. The metathesis activity of the catalysts at 298K was measured by using pure propene under atmospheric pressure. The oxidation number of rhenium on PDA was very high, and that on DA was zero-valent with highly dispersed state. The prepared Re/DA catalyst was easily activated by treating with oxygen gas at low temperatures after thermal decomposition at high temperatures. The activity of Re/DA catalyst, even with very low rhenium loading, was much higher than that of Re/PDA or conventional Re₂O_7/Al₂O ₃catalysts. Therefore, rhenium carbonyl was effective for preparing a highy active metathesis catalyst with very low rhenium loading. Rhenium ion on Re/DA catalyst seemed to be bonded to two oxygen atoms on DA surface, that is, two-valent. The two-valent rhenium ion was changed to about six-valent by treating with oxygen. It could be considered that propene metathesis occurred through carbene complex which was formed on the six-valent rhenium ions.

[자료제공 : 네이버학술정보]
×