【作者】 朱琼霞；

【导师】 褚道葆；

【作者基本信息】 安徽师范大学 ， 有机化学， 2003， 硕士

【摘要】 随着世界经济的进一步发展，由 CO₂导致的环境问题已引起人们的高度重视。如何减少大气中 CO₂的含量，缓解“温室效应”，已成为世界关注的焦点。电化学方法固定 CO₂具有反应条件温和、对环境友好的优点，属于“绿色化学”方法，近年来受到化学工作者的普遍关注。本论文研究了铂、锡修饰纳米TiO₂电极电催化还原 CO₂及其电解固定产物的结构表征，主要内容分为下面三部分：一. 铂、锡微粒修饰纳米TiO₂电极的制备及电化学测试。采用“牺牲”金属阳极法电合成TiO₂前驱体—钛酸乙酯，经水解、涂膜、煅烧制备纳米TiO₂膜电极；采用电沉积法将铂、锡微粒分散在纳米TiO₂膜表面。通过电化学暂态法研究了纳米TiO₂膜电极及铂、锡微粒修饰纳米TiO₂电极在 CO₂还原中的电催化活性。发现三种电极对 CO₂还原均具有催化活性。二. 铂、锡微粒修饰Ti/nano-TiO₂电极上 CO₂的电化学还原固定。在0.5M KHCO3溶液中分别采用控电流、控电位方式进行 CO₂的电解固定，反应在常温、常压下进行，分别以铂、锡修饰纳米TiO₂电极作阴极，研究了 CO₂的电解还原固定。化学检验方法及高效液相色谱法（HPLC）对溶解在溶液中的 CO₂还原产物进行初步分析表明产物为极性物质，化学性质活泼。三. CO₂的电化学固定产物的表征及结构确定。采用HPLC、紫外光谱（UV）、质谱（MS）、红外光谱（IR）、核磁共振波谱（1HNMR）等手段对 CO₂还原产物进行表征，经综合分析确定产物的分子量为258，分子式为C11H14O7，为一含有共轭链的多羰基化合物，这个结果在CA分子式检索中尚未发现，是一新的化合物。更多还原

【Abstract】 With the further development of global economy, environment problems resulted from CO₂ had got much serious considerations. It has become a world focus that how to reduce CO₂ in the air, buffering "greenhouse effect". The electrochemical fixation of CO₂ has the advantages that reactive conditions are mild and it is friendly to environment, which belongs to "green chemistry" methods and recently receives great attentions from chemists.The electrocatalytic reduction of CO₂ on nanocrystalline TiO₂ electrodes modified by Pt or Sn were investigated and the electrolytic fixed product was structurally characterized in this paper, which was composed of three parts:First, preparations and electrochemical tests of Pt or Sn particulates modified nano- TiO₂ electrodes. TiO₂ precursor, Ti（OEt）4, which was directly hydrolyzed, coated, and calcined to produce nano-TiO₂ film electrode, was electro-synthesized using sacrificial metal anode method. Nanocrystalline TiO₂ -Pt（or Sn） modified titanium electrodes were prepared by electro- depositing Pt or Sn particulates on nanocrystalline TiO₂ film. Electrocatalytic activities of Ti/nano-TiO₂ and Ti/nano-TiO₂-Pt（or Sn） electrodes in the reduction of CO₂ were studied by electrochemically transient methods. The results showed that the three electrodes have electrocatalytic activities in the reduction of CO₂ all.Second, the fixation of CO₂ on Ti/nano-TiO₂-Pt（or Sn） electrodes were investigated by controlled-voltage or controlled-current electrolysis in 0.5M KHCO3 solution under room temperature and ambient pressure. Electrolysis fixed product resolved in solution of CO₂ were identified using HPLC method and chemical tests, which revealed that reduced products are polar matter and chemically active.Finally, analysis and characterization of reduced product of CO₂ using HPLC, UV, IR, MS，and 1HNMR methods were carried out. According to analysis by synthesis on the four spectra of product, molecular weight was determined to be 258, and molecular formula C11H14O7. The product is a conjugated multiple-carbonyl compound and it is a new compound, due to not been searched out in CA formula index.更多还原