Synthesis of C_<2+> Alcohols from Syngas over Supported Metal Catalysts Containing Small Amounts or Rh

少量Rh负载型金属催化剂上合成气合成C_<2>醇

基本信息

批准号：
05650784
负责人：
KISHIDA Masahiro
金额：
$ 1.15万
依托单位：
KYUSHU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1993
资助国家：
日本
起止时间：
1993 至 1994
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05650784/
关键词：
CO Hydrogenation Lower Alcohols Ir-Mo-Rh catalyst Novel Catalyst Preparation Low Rh Content

项目摘要

Monometallic catalysts, Ir and Mo, were extremely low in activity and yielded hydrocarbon as main products. On the other hand, Ir-Mo bimetallic catalyst exhibited an high activity, and an increase in the selectivity to the C_<2+> alcohols was observed on the bimetallic catalyst. Mo dioxide was formed in the Mo monometallic catalyst while Mo metal was formed in the Ir-Mo catalyst. This suggests that Mo was reduced with hydrogen species migrated from Ir metal. From the TPR experiment, it was suggested that CO adsorbed on Ir also migrates onto Mo, and that CO and hydrogen reacted over Mo metal.It was found that Ir-Mo-Rh supported on silica containing small amounts of Rh exhibited much higher activity for Co hydrogenation than Ir-Mo bimetallic catalyst. The selectivity to various alcohols did not change very much upon the addition of Rh. The activity was greatly affected by the impregnation procedure of the metals in the catalyst preparation. The increase of selectivity to C_<2+> alcohols was investigated, and it was found that use of zirconia support and the addition of Li enhanced the selectivity of C_<2+> alcohols.We proposed a novel preparation method of supported metal catalysts using microemulsions. It was found that silica-supported Rh catalyst prepared by this method had extremely small rhodium particles, and that their size distribution was appreciably narrow. This catalyst exhibited much higher activity for the CO hydrogenation than the conventional catalysts prepared by impregnation, and showed high selectivity to C_<2+> alcohols as well as the conventional catalysts.

IR和MO的单金属催化剂的活性极低，并作为主要产物产生碳氢化合物。另一方面，IR-MO双金属催化剂表现出很高的活性，并且在双金属催化剂上观察到对C_ <2+>醇的选择性的提高。 MO二氧化基于MO单金属催化剂，而MO金属在IR-MO催化剂中形成。这表明MO通过从IR金属迁移的氢种类减少。从TPR实验中，提出吸附在IR上的CO也迁移到MO上，并且CO和氢通过Mo Metal反应。它发现在含有少量RH的二氧化硅上支持的IR-MO-RH对CO氢的活性比IR-MO-MO Bimetallic catalyst所表现得更高。添加RH时，对各种醇的选择性不会发生太大变化。该活性受到催化剂制备中金属的浸渍程序的极大影响。研究了对C_ <2+>醇的选择性的提高，发现使用氧化锆支持和LI的添加增强了C_ <2+>醇的选择性。我们提出了一种新型的使用微乳液的支持金属催化剂的准备方法。发现该方法制备的二氧化硅支持的RH催化剂具有极小的若度颗粒，并且它们的尺寸分布明显狭窄。该催化剂对CO氢化的活性比通过浸渍制备的常规催化剂高得多，并且对C_ <2+>醇以及常规催化剂的选择性高。