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.

通过二氧化碳的催化转化可持续地生产燃料是一个研究领域，有可能加强国家能源安全，同时提供一种机制，尽量减少二氧化碳的直接排放。先前关于CO2光还原为燃料的研究利用了基于TiO 2的催化剂。利用TiO 2作为光催化剂用于CO2光还原存在的主要挑战是通过光照射形成的电子-空穴对的快速复合。需要电子来通过还原CO2产生产物。努力使电荷复合最小化对于增强产物形成是至关重要的。尽管过去努力使用金属和非金属改性剂来改性基于TiO 2的催化剂，但公开的数据显示有用产物的生产率相对较低。典型的产物包括CO和有价值的燃料产物如CH 4和CH 3OH。几种催化剂导致多种产物的形成，导致在催化剂在实际应用中需要气体分离技术。亚利桑那州立大学的Jean Andino教授实验室的初步实验表明，RGO-TiO 2、还原氧化石墨和二氧化钛的复合催化剂很有希望。当TiO 2被光激活时，RGO可以潜在地帮助最小化电荷复合，从而使更多的电子可用于表面CO2还原反应。使用还原氧化石墨的潜在挑战是层间间距是否足以允许TiO 2驻留在RGO层之间。具有增加的层间间距的修改的RGO结构将减轻这种担忧。此外，如果用于RGO的改性剂与烃相比能够选择性地吸引CO2，则这可以允许增强的功能性。已发表的数据表明，CO2被强烈吸引到离子液体。Andino假设离子液体（IL）官能化的RGO-TiO 2将导致CO2的吸引，TiO 2内的充分电荷分离（使电子可用于CO2光还原反应），和排斥产生的烃，如CH 4，Andino已经进行了初步的工作来合成IL-RGO/TiO 2催化剂，并测试该催化剂在水蒸气存在下将CO2还原成烃的特性。DRIFTS研究表明，IL-RGO/TiO 2催化剂似乎导致在没有任何CO的情况下选择性和快速形成CH 4。由CO2光还原的CH 4产生速率比任何其他研究小组发表的高30倍以上。结果（结合文献数据）表明，新开发的IL-RGO/TiO 2催化剂产生CH 4的速率远远上级现有的任何其他催化剂，这是获得EAGER奖的理想基础。研究人员通常使用GC技术来量化数据，而不是DRIFTS IR光谱技术。此外，需要知道氧气存在对产物产率的影响。拟议的EAGER奖将提供必要的数据，以确认观察，并产生额外的数据，以支持全面的调查。EAGER预计将在催化领域产生几个更广泛的影响，并将扩大该领域的参与。首先，将产生的数据将有助于确定IL-RGO/TiO 2催化剂在直接和选择性产生有价值的燃料（CH 4）中的有用性。这项工作可能在国家能源安全和控制二氧化碳排放方面产生重大影响。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。在与社会有密切联系的拟议项目上工作的经验？的巨大挑战已经激励了这些学生，并有望帮助他们留在科学和工程。我们的期望是，这两个学生将取得足够的进展，使至少有一个同行评审的论文将提交和演示文稿在当地，也在年度会议上无论是美国化学学会，化学工程师的美国学会，或空气和废物管理协会在2013年。