二氧化碳的原位催化氢化反应

Upgrading use of carbon dioxide from waste to high valuable chemicals, materials, particularly to fuel-related products has attracted much research interest from a standpoint of green chemistry and sustainable development. However, the reactions involving CO2 are commonly carried out at high pressure, which may not be economically suitable and also pose safety concerns. The challenge is to develop efficient catalysts that are capable of activating CO2 under low pressure (preferably at 1 atm), and thus incorporating CO2 into organic molecules catalytically. On the other hand, there should generally be posed the inherent drawbacks associated with amine absorbents in current carbon capture and storage (CCS) processes, namely the requirement of two amines to capture one CO2, due to formation of ammonium carbamate, thus high energy demand for regeneration. Such undesired 2:1 stoichiometry would be a crucial barrier for future improvement of absorption capacity. A so-called CCU (carbon capture and utilization) strategy is proposed as an alternative approach to address the energy penalty problem in CCS process. The essence of our strategy is to use the captured CO2, also being considered as activated one, which could render this system suitable for accomplishing chemical transformation of CO2 to fuels e.g. formic acid and methanol via in situ catalytic hydrogenation under low pressure to avoid additional desorption step. Development of efficient absorbents with catalytic efficiency could be crucial for performing in situ hydrogenation of the captured CO2. Development of highly effective catalysts for the hydrogenation of gaseous CO2 and its derivatives for example, formate, carbonate and carbamate would be a prerequisite to realize in situ hydrogenation of the captured CO2 with simultaneous activation. It is a key point to design highly active catalysts on the basis of gaining insight into the reaction mechanism associated with activation of C=O band and formation of C-H band at a molecular level, and the relationship between electronic, steric factors, the reaction parameters and catalyst performance. On the other hand, the selectivity can be controlled by metal center, ligand and additive. In short, main purpose of this project is to develop high effective catalyst systems such as transition metal Ni/Fe based catalyst and organic catalysts including functionalized ionic liquid, frustrated Lewis pairs for undergoing in situ hydrogenation of CO2 into formic acid and methanol. This study would stimulate further interest in academic research and industrial development that may lead to utilizing CO2 as a renewable chemical feedstock in organic synthesis.

二氧化碳"变废为宝，高值化利用"的研究，特别是将二氧化碳还原为甲酸、甲醇等能源类产品，具有很高的科学意义以及应用价值。针对碳收集、储存方法中压缩、脱附过程的高能耗问题，本项目设计并合成既能捕集又能催化活化二氧化碳的高效催化材料，将二氧化碳的吸附技术与二氧化碳的催化氢化反应相耦合，避免能耗高的脱附过程，实现低压、温和条件下将二氧化碳原位催化转化为甲酸、甲醇（二氧化碳的间接还原反应）。 构建二氧化碳及其衍生物（甲酸酯、氨基甲酸酯、碳酸酯）的高效催化体系是实现其原位催化氢化反应的关键。因此，在探讨C=O键的活化机理、C-H键的形成机理及催化剂结构、反应参数的影响规律基础上，重点开发环境友好的金属铁、镍等以及有机小分子（功能化离子液体、立体受阻的路易斯酸碱对等）催化体系。建立二氧化碳催化转化方法及环境友好的两相反应工艺。 本项目研究对于二氧化碳的高效转化利用，具有重要意义和很高的应用价值。

二氧化碳"变废为宝，高值化利用"的研究，特别是将二氧化碳还原为甲酸等能源类产品，具有很高的科学意义以及应用价值。本项目设计并合成既能捕集又能催化活化二氧化碳的高效催化材料，将二氧化碳的吸附技术与二氧化碳的催化氢化反应相耦合，实现低压、温和条件下将二氧化碳原位催化转化为甲酸（二氧化碳的间接还原反应）。构建二氧化碳及其衍生物（甲酸酯、氨基甲酸酯、碳酸酯）的高效催化体系是实现其原位催化氢化反应的关键。因此，在探讨C=O键的活化机理及催化剂结构、反应参数的影响规律基础上，重点开发环境友好的金属催化剂以及功能化离子液体催化体系。建立了二氧化碳催化转化方法。 本项目研究对于二氧化碳的高效转化利用，具有重要意义和很高的应用价值。