复合金属氧化物上DMA与CO2加氢高效制备DMF的催化行为研究

The preparation of highly value-added N,N-dimethylformamide (DMF) by hydrogenation of CO2 and dimethylamine (DMA) is one of the important ways to high-value utilization of CO2. It is still a challenge for synthesis DMF with high selectivity through CO2 hydrogenation because of the difficulty to improve the selectivity of DMF over supported metal catalysts (palladium, ruthenium, copper, etc.). It is a good strategy to realize the synthesis of DMF with high selectivity through CO2 hydrogenation by using composite metal oxide catalysts, which present the active sites for DMA, CO2 activation and H2 activation respectively through ALD method. The DMF can be synthesized by C-N bond coupling and the selective cleavage of C-O bond. The structure-activity relationship of the composite metal oxides composite catalysts in the preparation of DMF was revealed by investigating the effects of the composition and the synergistic effect among the components of the composite metal oxides, as well as the adsorption and activation abilities of DMA, CO2 and H2 on the reaction activity and selectivity. In order to elucidate the reaction pathway and the mechanism of the hydrogenation of CO2 to DMF in the formation of C-N bonds and the selective cleavage of C-O bonds, the surface adsorbed species are identified, and the catalytic active sites are also characterized. The highly efficient catalysts, which is benefit for the activation and conversion of DMA and CO2 to DMF, are constructed.

由二甲胺（DMA）与CO2加氢制备N,N-二甲基甲酰胺（DMF）是高值化利用CO2的一条重要途径。针对该反应体系中金属（钯、钌、铜等）对H2活化能力较高引起C=O被过度加氢而造成DMF选择性低等缺点，本申请采用优化的合成方法，筛选能够高效吸附活化DMA、CO2及温和活化H2的金属氧化物组分，制备复合金属氧化物催化剂体系。利用ALD可控的单原子层沉积技术在催化剂表面构建纳米尺度上有效协同的多活性位点，实现C-N构建与C-O选择性加氢裂解来高效制备DMF。研究该体系中金属氧化物的组成、组分之间在纳米尺度上的协同，对DMA、CO2与H2的吸附活化以及对反应活性和选择性的影响规律，揭示催化剂在该反应中的构效关系。借助对表面吸附态物种的鉴别、中间物种的捕获和催化剂活性位的表征，认识该反应中C-N形成及C-O选择性断裂的路径和机理，从原子水平上构筑有利于DMA与CO2加氢制备DMF更高效的催化剂体系。

由二甲胺（DMA）与CO2加氢制备N,N-二甲基甲酰胺（DMF）是高值化利用CO2的一条重要途径。针.对该反应体系中金属（钯、钌、铜等）对H2活化能力较高引起C=O被过度加氢而造成DMF选择性低等缺.点，本研究采用优化的合成方法，筛选出能够高效吸附活化DMA、CO2及温和活化H2的金属氧化物组分，.制备了复合金属氧化物催化剂体系。利用ALD可控的单原子层沉积技术在催化剂表面构建纳米尺度上有效.协同的多活性位点，实现C-N构建与C-O选择性加氢裂解来高效制备DMF。研究了该体系中金属氧化物的组.成、组分之间在纳米尺度上的协同，对DMA、CO2与H2的吸附活化以及对反应活性和选择性的影响规律.，揭示了催化剂在该反应中的构效关系。借助对表面吸附态物种的鉴别、中间物种的捕获和催化剂活性.位的表征，认识到该反应中C-N形成及C-O选择性断裂的路径和机理，从原子水平上构筑了有利于DMA与CO2.加氢制备DMF更高效的催化剂体系。