EAGER: Electrochemical Reactor for Spontaneous Power Generation and CO2 Capture

1005303Mustain本项目的目的是验证以下假设：i)具有焦绿盐结构的碱土氧化物可以在碱性电化学反应器中选择性地将O2和大气中的CO2还原为co -2；Ii)与氢氧循环操作相比，使用碳酸盐阴离子操作反应器减少了最先进的阴离子交换膜的降解；iii) H2和甲醇可以在Pt表面与碳酸盐阴离子进行电化学氧化。与质子和氢氧交换膜燃料电池相比，这些基础性的发现将有助于开发一种运行在碳酸盐阴离子循环上的室温电化学反应器，其成本更低，耐久性更高。除了产生能量，这种电池还可以作为二氧化碳泵。以及净化装置。阳极排出的二氧化碳和水可以分离，用于化学处理或隔离。在这项工作中，将测试三种焦氯化物结构（A2B2O7）氧还原电催化剂：Ca2Pt2O7， Ca2Ru2O7和Ca2W2O7。之所以选择钙基氧化物，是因为其根氧化物CaO的表面碱度已知，这将允许在催化剂表面优先吸附CO2而不是H2O。焦绿盐结构的氧化物避免了碱土氧化物的常见缺陷，包括低电子导电性和表面钝化物质的形成。Pt， Ru和W ?B？由于金属在碱性介质中具有激活分子氧的能力，因此将对其进行研究。用SEM/EDS、XRD、BET和XPS对催化剂进行了表征。Pt电催化剂将在阳极上进行研究，在阳极上氧化两种常见燃料H2和CH3OH，并检查它们的动力学。所有电化学测量将在定制的三电极电池中进行。最后，研究了6种市售阴离子交换膜在高浓度KOH和HCO3-/CO3-2存在下的化学稳定性和离子电导率。研究结果将提供有关阴极氧化物的表面吸附和电子转移行为的信息，以及有关电化学反应器设计的信息，特别是电化学界面的构建、维护和稳定。此外，PI将使用单个组件构建一个实验室规模的5平方厘米的电化学反应器，在碳酸盐循环上运行，并展示其在各种操作条件下的性能。更广泛的影响教育目标是在PI内建立与电化学科学和工程相关的教与学链。康涅狄格大学的一个研究小组说。这将：i)让本科生参与研究活动；Ii)培养研究生；iii)允许在PI中进行实践研究？通过美国国家科学基金会资助的康涅狄格大学的焦耳研究员项目，为哈特福德公立学校的一名中学教师提供实验室；iv)在档案期刊上传播科学进展。研究和教育活动将加强发现和理解，同时促进多层次的教学、培训和学习。此外，该结果可能对许多重要系统产生深远的影响，包括：燃料电池，电池，生物柴油油的异质酯交换，电化学辅助碳封存，减少汽车污染预防中的氮氧化物以及水处理和电解。这方面的成功可以催化电化学发电装置理念的变革，重新获得公共、私人和立法部门对替代能源技术的支持，并产生具有成本效益、环保的绿色能源，并有可能在21世纪及以后实现净负二氧化碳足迹。

1005303Mustain The objective of this project is to test the hypotheses that: i) alkali earth oxides with the pyrochlore structure can selectively reduce O2 and atmospheric CO2 to CO3-2 in an alkaline electrochemical reactor; ii) operating the reactor with carbonate anions reduces the degradation of stateof- the-art anion exchange membranes compared with operation on the hydroxide cycle; and iii) H2 and methanol can be electrochemically oxidized on Pt surfaces with carbonate anions. These fundamental discoveries will allow for the development of a room temperature electrochemical reactor operating on the carbonate anionic cycle with reduced cost and increased durability compared to both the proton and hydroxide exchange membrane fuel cells. In addition to producing energy, this cell also acts as a CO2 ?pump? and purification device. The anode effluent CO2 and water can be separated and either utilized in chemical processing or sequestered.In this work, three pyrochlore structured (A2B2O7) oxygen reduction electrocatalysts will be tested: Ca2Pt2O7, Ca2Ru2O7 and Ca2W2O7. A calcium-based oxide was selected due to the known surface basicity of its root oxide, CaO, which will allow for the preferential adsorption of CO2 over H2O on the catalyst surface. The pyrochlore structured oxide avoids common pitfalls of alkali earth oxides, including low electronic conductivity and the formation of surface passivating species. Pt, Ru and W ?B? metals will be investigated because of their ability to activate molecular oxygen in alkaline media. The resulting catalysts will be fully characterized by SEM/EDS, XRD, BET and XPS. Pt electrocatalysts will be investigated at the anode, where two common fuels, H2 and CH3OH, will be oxidized and their kinetics examined. All electrochemical measurements will be conducted in a custom-built three electrode cell. Finally, the chemical stability and ionic conductivity of six commercially available anion exchange membranes will be investigated in the presence of both concentrated KOH and HCO3-/CO3-2.The results will yield information regarding surface adsorption and electron transfer behavior of the cathode oxides, information regarding electrochemical reactor design, specifically the construction, maintenance and stabilization of the electrochemical interface. Also, the PI will use the individual components to construct a laboratory scale, 5 cm2 electrochemical reactor operating on the carbonate cycle and demonstrate its performance under various operating conditions.Broader ImpactsThe educational objective is to establish a teaching and learning chain related to electrochemical science and engineering within the PI?s group at the University of Connecticut. This will: i) involve an undergraduate student in the research activities; ii) train a graduate student; iii) permit hands-on research in the PI?s laboratory for a Hartford Public School secondary school teacher through the NSF-sponsored Joules-Fellows program at the University of Connecticut; and iv) disseminate the scientific advances in archival journals.The research and educational activities will enhance discovery and understanding while promoting teaching, training and learning across multiple levels. Also, the results could have far reaching impact on many important systems including: fuel cells, batteries, heterogeneous transesterfication of oils for biodiesel, electrochemically assisted carbon sequestration, reduction of nitrous oxides in automotive pollution prevention and water treatment and electrolysis. Success in this regard could catalyze a transformative shift in philosophy regarding electrochemical energy generation devices, renew public, private and legislative support for alternative energy technologies and yield a cost-effective, environmentally green energy source with the potential for a net negative CO2 footprint for the 21st century and beyond.