气候变化领域集成服务门户(CCPortal): Cu complexes-catalyzed reduction of carbon dioxide tomethanol with NaBH4 [Cu配合物催化硼氢化钠还原CO2制备甲醇]

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DOI	10.1360/TB-2020-0052
	Cu complexes-catalyzed reduction of carbon dioxide tomethanol with NaBH4 [Cu配合物催化硼氢化钠还原CO2制备甲醇]
	Wang W.-H.; Liu P.; Qiu L.-C.; Wang J.; Bao M.
发表日期	2020
ISSN	0023074X
起始页码	3438
结束页码	3445
卷号	65 期号:31
英文摘要	Carbon dioxide is one of the most important greenhouse gases and leads to serious global warming. Therefore, transformation of CO2 to fuels such as methanol to establish methanol economy and mitigate CO2 emission has attracted much more attention. Homogeneous hydrogenation of CO2 to methanol is suffering from low catalytic activity and hash reaction conditions. Although hydroboration of CO2 to methanol can proceed under mild conditions, most of the hydrogen sources, such as BH3, HBCat, 9-BBN, and HBpin, are expensive, sensitive to air, and difficult to operate. Development of efficient catalytic system with cheap catalyst and hydrogen source under mild conditions is highly desirable. In this study, we developed a novel catalytic system using cheap Cu salts and N,N-bidentate ligands such as N,N,N',N'- tetramethylethylenediamine (TMED), N,N'-dimethyl-1,2-ethanediamine, ethylenediamine, and 2,2'-bipyrimidine, as in situ catalysts to catalyze hydroboration of carbon dioxide to methanol. The influences of metal salts, anions, ligands, and solvents on catalytic reaction were examined. The optimized conditions were determined as: 0.02 mmol CuI, 0.02 mmol TMED, 6 mmol NaBH4, 10 mL THF, P(CO2) = 1 atm, 25℃. The results indicated that CuI/TMED, CuI/N,N'-dimethyl-1,2-ethanediamine, CuI/ethylenediamine, and CuI/2,2'-bipyrimidine could efficiently catalyze the reduction of carbon dioxide to methanol with sodium borohydride under ambient temperature and pressure. CuI/TMED (0.01 mmol) catalyst achieved a highest TON of 315 at 25℃ under 1 atm CO2 for 12 h. A high yield of 47% for methanol was obtained after 24 h when CuI/TMED was used as catalyst under optimal conditions. These results suggest that the in situ Cu catalyst is highly efficient for CO2 reduction to methanol with NaBH4. To understand the reaction mechanism, a systematic study with in-situ FTIR and 1H NMR were carried out. In-situ FTIR indicated generation of intermediates HCOOBX3, CH3OBX3 (X = H, HCOO, MeO), and L-Cu-O2CH. 1H NMR spectra of TMED, TMED + NaBH4, CuI/TMED + NaBH4 in d-THF suggested that CuI and TMED form complex in THF and the in situ complex can coordinate BH4-. A peak at 3.48 ppm for Cu hydride was also observed. Based on the experimental results and previous research results, we proposed a mechanism for hydroboration of carbon dioxide catalyzed by CuI/TMED. Boron-derived species (BX3) is supposed to act as a Lewis acid that can activate formate by coordinating with carbonyl group and facilitate further reduction by Cu hydride to generate methanol. This study developed efficient catalytic system for CO2 reduction to methanol with NaBH4 under mild conditions using cheap Cu metal and N,N-bidentate ligands. Mechanistic study provided insightful information for the catalytic process. © 2020, Science Press. All right reserved.
英文关键词	Carbon dioxide reduction; Cu complex; Methanol; N,N-bidentate ligand; Sodium borohydride
scopus关键词	Carbon dioxide; Carbon dioxide process; Catalysis; Catalyst activity; Fourier transform infrared spectroscopy; Global warming; Greenhouse gases; Hydrides; Hydrogen; Ligands; Methanol; Methanol fuels; Nuclear magnetic resonance spectroscopy; Salts; Sodium Borohydride; Catalytic reactions; Mechanistic studies; Optimal conditions; Optimized conditions; Reaction conditions; Reaction mechanism; Temperature and pressures; Tetramethylethylenediamine; Copper compounds
来源期刊	Kexue Tongbao/Chinese Science Bulletin
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/176762
作者单位	State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian, 116023, China; School of Chemical Engineering, Dalian University of Technology, Panjin, 124221, China
推荐引用方式 GB/T 7714	Wang W.-H.,Liu P.,Qiu L.-C.,等. Cu complexes-catalyzed reduction of carbon dioxide tomethanol with NaBH4 [Cu配合物催化硼氢化钠还原CO2制备甲醇][J],2020,65(31).
APA	Wang W.-H.,Liu P.,Qiu L.-C.,Wang J.,&Bao M..(2020).Cu complexes-catalyzed reduction of carbon dioxide tomethanol with NaBH4 [Cu配合物催化硼氢化钠还原CO2制备甲醇].Kexue Tongbao/Chinese Science Bulletin,65(31).
MLA	Wang W.-H.,et al."Cu complexes-catalyzed reduction of carbon dioxide tomethanol with NaBH4 [Cu配合物催化硼氢化钠还原CO2制备甲醇]".Kexue Tongbao/Chinese Science Bulletin 65.31(2020).