EAGER: Bimetallic nano-structures as versatile photocatalysts

热切：利用双金属纳米结构作为高效太阳能驱动化学转化的催化剂用于生产商品化学品的大多数化学转化过程都是完全使用热能进行的，在美国化学工业中，50%的能源消耗用于原料，而另外50%提供热能来驱动化学反应和净化步骤。显然，必须发展在较低温度和较高选择性下操作的化学过程，以提高能源和原子（原料转化为产品）效率。该奖项授予了加州大学河滨分校的Phillip Christopher教授，该奖项将允许探索一类新的材料，这些材料有潜力克服热驱动过程的固有限制，并允许在较低温度下以更高的选择性进行太阳能辅助化学转化。这些新型催化剂是一种杂化材料，采用非常特殊的银种与太阳能和其他金属相互作用，这将提高反应的选择性。这项研究通过引入新的工艺，开始解决从燃烧化石燃料到驱动化学过程的环境问题，有可能产生重大的社会影响。克里斯托弗计划通过实践研究和课堂教育，为不同的观众提供多学科的教育经验。具体来说，已经与河滨社区学院（RCC）建立了关系，将为这个为期两年的西班牙裔服务机构的学生提供在克里斯托弗实验室实习的机会。对于RCC学生来说，这将是一个有用的经验，帮助他们从社区学院式的教育过渡到主要的研究型大学，激发他们对基础研究的兴趣，从而鼓励他们参加学士学位以外的教育。年代的水平。该项目将对新一代材料的合成和光催化特性进行基础研究，这些材料有可能在广泛的工业化学和燃料生产过程中提高能源效率和化学选择性。该项目的总体愿景是研究混合材料，利用银与太阳光谱的独特相互作用和更多功能金属（Pt）的优异催化功能，选择性地驱动重要的化学反应，利用太阳能。本文将采用种子介导法合成由银纳米粒子芯和铂壳或沉积粒子组成的异质结构双金属纳米粒子。银纳米立方将通过多元醇工艺合成，并通过在水溶液中还原Pt盐将Pt沉积在预合成的银立方上。关键的合成条件包括温度、前驱体注入速度和还原剂强度来控制生长机制，并使用多种方法来表征所得结构。将测试纳米结构在CO氧化反应中的活性，作为温度、反应物分压、照明强度和波长的函数。结果将与仅由Pt和Ag组成的控制催化剂在绝缘和半导体支架上进行比较，以证明Pt/Ag双金属纳米结构的独特性能。双金属等离子体纳米结构独特的光催化反应性的证明，将为利用太阳能选择性地驱动更广泛的化学反应开辟道路，而不是在当前类别的半导体基光催化剂上执行。

EAGER: Utilizing bimetallic nanostructures as catalysts for efficient solar-driven chemical conversionA majority of chemical conversion processes utilized for the production of commodity chemicals are carried out using exclusively thermal energy, where 50% of the energy consumed in the United States chemical industry is required for feedstocks, while the other 50% provides thermal energy to drive chemical reactions and purification steps. It is apparent that chemical processes operating at lower temperature and higher selectivity must be developed to enhance energy and atomic (feed stock conversion to product) efficiencies. This EAGER award made to Professor Phillip Christopher at University of California Riverside will permit a new class of materials to be explored that have the potential to overcome the inherent limitations of thermal driven processes and allow for solar-assisted chemical conversions at lower temperatures and with higher selectivities. These new catalysts are hybrid materials employing very specific silver species for their interactions with solar energy and other metal species which will improve the selectivity for reactions. This research has potential for significant societal impact through the introduction of new processes that begin to address environmental concerns from burning fossil fuels to drive chemical processes. Christopher plans to include multidisciplinary educational experiences for a diverse audience through hands on research and in class education. Specifically, a relationship with Riverside Community College (RCC) has been developed that will give students from this two-year Hispanic Serving Institution internship opportunities in the Christopher laboratories. This will be a useful experience for RCC students to facilitate their transition from a community college style education to a major research University and to spark their interest in basic research, thus encouraging their enrollment in education beyond the Bachelor?s level.This project will undertake basic research into the synthesis and photocatalytic properties of a new generation of materials that have the potential to increase energy efficiency and chemical selectivity for a wide range of industrial chemical and fuel production processes. The overarching vision of this project is to investigate hybrid materials that exploit unique interactions of Ag with the solar spectrum and the excellent catalytic functionality of more versatile metals (Pt) to selectively drive important chemical reactions using solar energy. Hetero-structured bimetallic nanoparticles consisting of Ag nanoparticle cores and Pt shells or deposited particles will be synthesized using a seed mediated process. Ag nanocubes will be synthesized via the polyol process and Pt will be deposited on pre-synthesized Ag cubes by reduction of Pt salts in an aqueous solution. Crucial synthesis conditions including temperature, precursor injection rate and reductant strength will be varied to control the growth mechanism, and the resulting structures will be characterized using numerous methods. Nanostructures will be tested for their activity in the CO oxidation reactions as a function of temperature, reactant partial pressure, illumination intensity and wavelength. The results will be compared to control catalysts consisting only of Pt and Ag on insulating and semiconducting supports to demonstrate unique properties of the bimetallic Pt/Ag nanostructures. The demonstration of unique photocatalytic reactivity of bimetallic plasmonic nanostructures will open avenues towards the use of solar energy to selectively drive a much wider range of chemical reactions than executable on current classes of semiconductor-based photocatalysts.