Low-temperature methanol synthesis in liquid-phase with a Raney Nickel–alkoxide system: effect of Raney Nickel pretreatment and reaction conditions
Low-temperature methanol synthesis in liquid-phase with a Raney Nickel–alkoxide system: effect of Raney Nickel pretreatment and reaction conditions
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雷尼镍-醇盐体系液相低温合成甲醇：雷尼镍预处理和反应条件的影响
DOI：
10.1016/s1381-1169(98)00267-2
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发表时间：
1999
影响因子：
--
通讯作者：
K. Aika
中科院分区：
文献类型：
--
作者：
Eun Sook Lee;K. Aika
在234 ml高压釜中，采用Raney-Ni和CH 3 ONa组成的固定催化剂，在5 MPa、423 K和2 h的反应条件下进行CO液相加氢。通过在Raney-Ni催化剂的浸出之后除去水并且通过使用CH 3 ONa而不是CH 3CH 2 ONa来实现高生产率（CO转化率为92.4%，甲醇选择性为99.8%）。在高CO含量（CO/H2>2）条件下，反应后液相中出现Ni（CO）4。而当Raney-Ni和CH 3 ONa在423 K、5 MPa、2 h条件下以化学计量比（H2/CO=2）反应时，未观察到Ni（CO）4的生成。在这些条件下，CH_3OH的羰基化反应（CH_3ONa催化）似乎比Raney-Ni的羰基化反应更快。甲酸甲酯（MeF）在Raney-Ni催化剂上的氢解反应在443 K下同时生成甲醇和甲烷。而在化学计量比（H2/CO=2）、423 K、5 MPa、2 h条件下，Raney-Ni与CH 3 ONa反应时，没有副产物甲烷生成。反应的主要途径是甲醇在CH 3 ONa催化下羰基化生成MeF，然后MeF在Raney-Ni催化下氢解生成甲醇，但反应机理中存在Raney-Ni和CH 3 ONa的协同作用。
The CO hydrogenation in liquid-phase was carried out using a set catalyst composed of Raney-Ni and CH3ONa in an autoclave of 234 ml under the reaction condition of 5 MPa, 423 K and 2 h. A high productivity (CO conversion of 92.4% with methanol selectivity of 99.8%) was achieved by eliminating the water after leaching of the Raney-Ni catalyst and by using CH3ONa rather than CH3CH2ONa. Ni(CO)4was observed in the liquid-phase after the reaction under the condition of high CO content (CO/H2>2). However, the formation of Ni(CO)4was not observed, when stoichiometric gas ratio (H2/CO=2) was used with Raney-Ni and CH3ONa at 423 K, 5 MPa, and 2 h. Carbonylation of CH3OH (CH3ONa catalysis) seems to be faster than the carbonylation of Raney-Ni to Ni(CO)4under these conditions. Hydrogenolysis of methyl formate (MeF) on the Raney-Ni yielded both methanol and methane at 443 K. However, the by-product methane was never obtained when using Raney-Ni with CH3ONa under the stoichiometric gas ratio (H2/CO=2) at 423 K, 5 MPa, and 2 h. The essential pathway must be the carbonylation of methanol to MeF with the CH3ONa catalyst followed by the hydrogenolysis of MeF to methanol with the Raney-Ni; however, the synergy effect between Raney-Ni and CH3ONa are suggested in the mechanism.