Collaborative Research: Experimental and Computational Studies on CO2 Photoreduction to Fuels by Nanostructured Catalysts

机构：威斯康星大学密尔沃基分校/亚利桑那州立大学标题：合作研究：纳米结构催化剂对二氧化碳光还原为燃料的实验和计算研究知识分子：大气中的二氧化碳（CO2）是生产可再生燃料的潜在可持续碳源。光催化将二氧化碳和水转化为碳氢化合物是一条特别有吸引力的途径，因为它使用太阳能作为还原电子的来源来驱动这一转化过程。然而，由于CO2具有稳定的热力学性质，光催化还原CO2是一项极具挑战性的任务。低收率的CO2转化需要更高效的光催化剂，但高效光催化剂的开发需要对CO2？从分子水平的计算研究中推导出催化剂相互作用和电子转移途径。本研究的总体目标是利用太阳辐射光催化，通过操纵催化剂组成和纳米结构，以高转化效率将CO2还原为燃料（CO、甲烷、甲醇和其他碳氢化合物）。为此，提出的研究有三个目标。第一个目标是制造纳米结构光催化剂，特别是含有混合相TiO2纳米颗粒的brookite，其相含量可控，如晶格掺杂碘和表面Cu簇，以实现可见光响应并促进电荷分离。第二个目标是通过紧密耦合实验和计算化学（密度泛函数理论）建模，对混合相（如锐钛矿-板岩）纳米晶界面上的催化剂性质和电荷分离机制有一个基本的了解。第三个目标是优化催化剂组成和纳米结构（如TiO2相组成、晶体尺寸、表面结构、掺杂剂浓度等），协同提高CO2光还原效率。在这方面，拟议的研究将结合实验和计算方法来评估基于brookite的催化剂对CO2光还原的活性，并将促进对材料科学，表面化学，光催化和纳米技术等多学科领域的基本理解。更广泛的影响二氧化碳和水光还原成碳氢化合物燃料的过程同时解决了温室气体管理和可再生燃料生产的挑战。教育和外联活动将在拟议研究的范围内进行。与二氧化碳减排和太阳能燃料相关的主题将被纳入亚利桑那州立大学（ASU）和威斯康星大学密尔沃基分校（UWM）的太阳能工程、化学反应堆设计和空气质量工程课程。由Ira A. Fulton工程学院（IAFSE）赞助的亚利桑那州立大学外展活动将为来自弱势群体的学生和当地教师提供太阳能燃料的实践经验。还将创建一个关于阳光转化二氧化碳的动画教育模块，以吸引学生和公众。该模块将发布在主要研究人员的网站以及ASU IAFSE外联网站上。威斯康星大学的免费推广活动将通过威斯康星州密尔沃基市的城市生态中心（UEC）进行协调，该中心与44所内城小学和高中建立了伙伴关系，并提供？户外教室吗?在城市青年科学教育方面。

Institution: University of Wisconsin-Milwaukee / Arizona State UniversityTitle: Collaborative Research: Experimental and Computational Studies on CO2 Photoreduction to Fuels by Nanostructured CatalystsIntellectual MeritCarbon dioxide (CO2) from the atmosphere is a potentially sustainable source of carbon for the production of renewable fuels. The photocatalytic conversion of CO2 and water to hydrocarbons is a particularly attractive route, as it uses solar energy as the source of reducing electrons to drive this conversion process. However, the photocatalytic reduction of CO2 is an extremely challenging task due to the stable thermodynamic properties of CO2. The low yield of CO2 conversion calls for more efficient photocatalysts, but the development of efficient photocatalysts requires understanding of CO2?catalyst interactions and electron transfer pathways deduced from computational studies at the molecular level. The overall objective of the proposed research is to use solar radiation to photocatalytically reduce CO2 to fuels (CO, methane, methanol, and other hydrocarbons) at high conversion efficiency through manipulation of catalyst composition and nanostructure. Toward this end, the proposed research has three objectives. The first objective is to fabricate nanostructured photocatalysts, specifically brookite-containing mixed-phase TiO2 nanoparticles with controlled phase contents such as lattice-doped iodine and surface Cu clusters, to achieve visible light responsiveness and facilitate charge separation. The second objective is to develop a fundamental understanding of the catalyst properties and charge separation mechanism at the mixed-phase (e.g., anatase-brookite) nanocrystalline interfaces through closely coupled experiments and computational chemistry (density functional theory) modeling. The third objective is to optimize catalyst composition and nanostructure (e.g., TiO2 phase composition, crystal size, surface structures, dopant concentration, etc.) to synergistically improve CO2 photoreduction efficiency. In this regard, the proposed research will integrate experimental and computational approaches to evaluate brookite-based catalyst activity toward CO2 photoreduction, and will advance fundamental understanding in the multidisciplinary areas of material science, surface chemistry, photocatalysis, and nanotechnology. Broader ImpactsProcesses for photoreduction of CO2 and water to hydrocarbon fuels tackle the simultaneous challenges of greenhouse gas management and renewable fuels production. The educational and outreach activities will be in the context of the proposed research. Topics related to CO2 reduction and solar fuels will be incorporated into solar engineering, chemical reactor design, and air quality engineering courses at Arizona State University (ASU) and the University of Wisconsin-Milwaukee (UWM). Outreach activities at ASU sponsored though the Ira A. Fulton Schools of Engineering (IAFSE) will provide hands-on experiences in solar fuels to students from underrepresented groups as well as local teachers. An animated educational module on CO2 conversion by sunlight will also be created to engage students and the general public. This module will be posted on the websites of the principal investigators as well as on the ASU IAFSE outreach website. Complimentary outreach activities at UWM will be coordinated through the Urban Ecology Center (UEC) in Milwaukee, Wisconsin, who has partnerships with forty-four inner-city elementary and high schools and provides ?outdoor classrooms? in science education for urban youth.