Interconversion between Formic Acid and H2/CO2 using Rhodium and Ruthenium Catalysts for CO2 Fixation and H2 Storage
Interconversion between Formic Acid and H2/CO2 using Rhodium and Ruthenium Catalysts for CO2 Fixation and H2 Storage
复制标题
DOI：
10.1002/cssc.201000327
复制
发表时间：
2011-01-01
期刊：
影响因子：
8.4
通讯作者：
Hirose, Takuji
中科院分区：
文献类型：
--
作者：
Himeda, Yuichiro;Miyazawa, Satoru;Hirose, Takuji
The interconversion between formic acid and H-2/CO2 using half-sandwich rhodium and ruthenium catalysts with 4,4'-dihydroxy- 2,2'-bipyridine (DHBP) was investigated. The influence of substituents of the bipyridine ligand was studied. Chemical shifts of protons in bipyridine linearly correlated with Hammett substituent constants. In the hydrogenation of CO2/bicarbonate to formate under basic conditions, significant activations of the catalysts were caused by the electronic effect of oxyanions generated by deprotonation of the hydroxyl group. Initial turnover frequencies of the ruthenium-and rhodium-DHBP complexes increased 65- and 8-fold, respectively, compared to the corresponding unsubstituted bipyridine complexes. In the decomposition of formic acid under acidic conditions, activity enhancement by the electronic effect of the hydroxyl group was observed for the ruthenium catalyst. The rhodium-DHBP catalyst showed high activity without CO contamination in a relatively wide pH range. Pressurized H-2 can be obtained using an autoclave reactor. The highest turnover frequency and number were obtained at 80 degrees C. The catalytic system provides valuable insight into the use of CO2 as a H-2 storage material by combining CO2 hydrogenation with formic acid decomposition.
