三维枝状双相Cu(0)/Cu2(I)O高效电催化CO2还原的研究

With such issues as energy crisis and environmental becoming increasingly severe, electrochemical reduction of CO2 to energy fuels and feedstock chemicals have gained much attention. Low cost and high abundant Cu is known as one of electrocatalyts for efficient CO2 conversion to hydrocarbons. However, it is strongly limited by the high overpotential needed and low selectivity. In this project, in order to lower the overpotential and improve product selectivity for CO2 reduction, we will fabricate bi-phasic Cu(0)/Cu2(I)O with three dimensional (3D) dendritic structure and further manipulate its surface modification. We will focus on the following three aspects: 1) Prepare bi-phasic Cu(0)/Cu2(I)O electrode with 3D dendritic structure by electrodeposition; Investigate the influence of 3D dendritic structure and Cu(I) sites on the adsorption/transportation/diffusion of reactants and intermediates, which will improve specific product selectivity. 2) Modify the prepared electrode with phosphate ligands and metal porphyrin with _COOH functional groups; Investigate their effect on lowering overpotential and improving catalytic activity for CO2 reduction. 3) Build a full cell from the prepared Cu cathode and photoanode for photoelectrochemical CO2 reduction and water splitting, to further develop the system and fulfill efficient solar energy conversion to chemical energy.

随着能源危机和环境问题日益严重，电催化还原CO2生成能源产品和化学品引起广泛关注。铜是一个高效还原CO2的电催化材料，并且成本低储量丰富。然而，铜基电极催化还原CO2所需过电压较大且产物分布广选择性较低。本课题基于对三维枝状双相Cu(0)/Cu2(I)O电极的制备以及表面修饰的研究，旨在降低还原CO2所需过电压，提高产物的选择性。我们将从下面三个方面进行研究1）利用电沉积方法制备三维枝状双相Cu(0)/Cu2(I)O电极，考察三维枝状结构和Cu(I)位点对反应物和中间产物的吸附及扩散的调控作用，提高特定产物的选择性；2）对所制备的铜基电极进行表面修饰（磷酸根络合物、金属卟啉类_COOH），考察其降低过电压，提高催化还原CO2活性的作用；3）将所制备电极与光阳极构建成一个光电催化CO2还原和水解的整体电解装置，进一步利用光电调节CO2还原所需电压和产物选择性，实现太阳能-化学能的高效转换。

电催化还原二氧化碳生成高价值的化学品和燃料，不仅能实现能源的循环利用，还可解决温室效应带来的一系列生态问题，在能源和环境方面有着重大意义。铜是一个高效还原CO2的电催化材料，并且成本低储量丰富。然而，铜基电极催化还原CO2所需过电压较大且产物分布广选择性较低。针对这些问题，在本项目中，我们围绕铜基材料的设计与制备和电催化CO2还原进行研究，取得了如下成果：1）调节电沉积和后处理过程，制备出高效三维枝状铜基电极，显著提高了电催化CO2还原生成HCOO-和C2H4的选择性；2）设计合成了具有局域质子源的Cu、Fe等不同金属中心的卟啉配合物，提高了电催化CO2还原生成CO的活性；3）利用自组装和电化学沉积成功合成了Cu2O，Cu2O-Cu和Cu反蛋白石结构电极，Cu2O-Cu复合电极显示出良好的光学性能和电化学性能。