EAGER: Reduction of Carbon Dioxide to Methane

EAGER：将二氧化碳还原为甲烷

• 批准号: 1253443
• 负责人: Jean Andino
• 金额: $ 8.7万
• 依托单位: Arizona State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-01 至 2014-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1253443&HistoricalAwards=false
• 关键词: EAGER; Reduction; Carbon; Dioxide; Methane

Sustainable generation of fuels through the catalytic conversion of CO2 is an area of research that has the potential to enhance national energy security while simultaneously providing a mechanism to minimize direct CO2 emissions. Previous studies on CO2 photoreduction to fuels have utilized TiO2-based catalysts. A major challenge that exists with utilizing TiO2 as a photocatalyst for CO2 photoreduction is the fast recombination of electron-hole pairs which are formed by light irradiation. Electrons are needed to generate products via reduction of CO2. Efforts to minimize charge recombination are critical for enhancing product formation. Despite past efforts at modifying the TiO2-based catalysts using both metal and non-metal modifiers, published data shows relatively low production rates for useful products. Typical products include CO and valuable fuel products such as CH4 and CH3OH. Several of the catalysts resulted in the formation of multiple products, resulting in the need for gas separation technologies when the catalyst is implemented in a real-world scenario.Preliminary experiments in the laboratories of Professor Jean Andino at Arizona State University have shown promise for a composite catalyst of RGO-TiO2, reduced graphite oxide and titania. The RGO can potentially assist in minimizing charge recombination when TiO2 is activated by light, thereby making more electrons available for a surface CO2 reduction reaction. A potential challenge with using reduced graphite oxide is whether the interlayer spacing would be sufficient to allow TiO2 to reside between the RGO layers. A modified RGO structure with increased interlayer spacing would alleviate this concern. Moreover, if the modifier for the RGO is capable of selectively attracting CO2 as compared to hydrocarbons, then this may allow for enhanced functionality. Published data show that CO2 is strongly attracted to ionic liquids. Andino hypothesizes that an ionic liquid (IL) functionalized RGO-TiO2 would result in the attraction of CO2, sufficient charge separation within the TiO2 (making electrons available for the CO2 photoreduction reaction), and rejection of the produced hydrocarbons, such as CH4, thus reducing separation needs.Andino has performed preliminary work to synthesize the IL-RGO/TiO2 catalyst and to test the characteristics of the catalyst for the reduction of CO2 to hydrocarbons in the presence of water vapor. The DRIFTS studies showed the IL-RGO/TiO2 catalyst appears to lead to the selective and fast formation of CH4 in the absence of any CO. The CH4 production rate from CO2 photoreduction is more than 30 times higher than that which was published by any other research group. The results (taken in conjunction with literature data) suggest that the newly developed IL-RGO/TiO2 catalyst produces CH4 at a rate that is far superior to any other existing catalyst.This is an ideal basis for this EAGER award. Researchers typically use GC techniques to quantify the data and not the DRIFTS IR spectroscopy technique. Furthermore the impact of oxygen presence on product yield needs to be known. The proposed EAGER award will provide the necessary data to confirm the observation and generate additional data to support a full investigation.This EAGER is expected to have several broader impacts in the catalysis area and will broaden participation in the field. First, the data that will be generated will help to establish the usefulness of the IL-RGO/TiO2 catalyst in the direct and selective generation of a valuable fuel (CH4). This work could have significant impacts in the areas of national energy security and the control of CO2 emissions. The proposed project would be used to partially fund two traditionally underrepresented chemical engineering graduate students. The experience of working on the proposed project that has a strong connection to society?s grand challenges has already inspired these students, and is expected to help retain them in science and engineering. The expectation is that both students will make sufficient progress so that at least one peer-reviewed paper will be submitted and presentations made locally and also at annual meetings of either the American Chemical Society, the American Institute of Chemical Engineers, or the Air and Waste Management Association in 2013.

通过二氧化碳催化转化可持续生产燃料是一个研究领域，它有可能增强国家能源安全，同时提供一种最大限度减少直接二氧化碳排放的机制。先前关于二氧化碳光还原成燃料的研究使用了二氧化钛基催化剂。利用 TiO2 作为 CO2 光还原的光催化剂存在的主要挑战是光照射形成的电子-空穴对的快速复合。通过还原二氧化碳生成产物需要电子。尽量减少电荷复合对于增强产物形成至关重要。尽管过去努力使用金属和非金属改性剂来改性二氧化钛基催化剂，但已发表的数据显示有用产品的生产率相对较低。典型产品包括 CO 和有价值的燃料产品，例如 CH4 和 CH3OH。其中几种催化剂导致了多种产物的形成，因此在实际应用中需要使用气体分离技术。亚利桑那州立大学 Jean Andino 教授实验室的初步实验表明， RGO-TiO2、还原石墨氧化物和二氧化钛复合催化剂。当 TiO2 被光激活时，RGO 可能有助于最大限度地减少电荷重组，从而为表面 CO2 还原反应提供更多电子。使用还原石墨氧化物的一个潜在挑战是层间距是否足以让 TiO2 驻留在 RGO 层之间。改进的 RGO 结构以及增加的层间距将缓解这种担忧。此外，如果 RGO 的改性剂与碳氢化合物相比能够选择性地吸引 CO2，那么这可能会增强功能。已发表的数据表明，离子液体强烈吸引二氧化碳。 Andino 假设，离子液体 (IL) 功能化的 RGO-TiO2 会吸引 CO2，在 TiO2 内实现充分的电荷分离（使电子可用于 CO2 光还原反应），并排斥所产生的碳氢化合物，例如 CH4，从而减少分离需求。Andino 已进行了合成 IL-RGO/TiO2 催化剂的初步工作，并测试了该催化剂在水蒸气存在下将 CO2 还原为碳氢化合物的特性。 DRIFTS 研究表明，IL-RGO/TiO2 催化剂似乎可以在没有任何 CO 的情况下选择性且快速地形成 CH4。CO2 光还原产生的 CH4 生产率比任何其他文献发表的产率高 30 倍以上研究小组。结果（结合文献数据）表明，新开发的 IL-RGO/TiO2 催化剂产生 CH4 的速度远远优于任何其他现有催化剂。这是获得该 EAGER 奖项的理想基础。研究人员通常使用 GC 技术而不是 DRIFTS IR 光谱技术来量化数据。此外，需要了解氧气存在对产品收率的影响。拟议的 EAGER 奖项将提供必要的数据来确认观察结果，并生成额外的数据来支持全面的调查。该 EAGER 预计将在催化领域产生更广泛的影响，并将扩大该领域的参与。首先，生成的数据将有助于确定 IL-RGO/TiO2 催化剂在直接选择性生成有价值燃料 (CH4) 方面的有用性。这项工作可能会对国家能源安全和二氧化碳排放控制领域产生重大影响。拟议的项目将用于部分资助两名传统上代表性不足的化学工程研究生。与社会重大挑战密切相关的拟议项目的工作经验已经激励了这些学生，并有望帮助他们留在科学和工程领域。期望两名学生都能取得足够的进步，以便至少提交一篇经过同行评审的论文并在当地以及美国化学会、美国化学工程师学会或空气与废物协会的年会上进行演示2013年管理协会。