SNM-IS: Scalable Biomineralization of Functional Oxide Nanoparticles and Nanostructures for Environmental and Energy Applications

这一研究项目旨在创造一种可扩展的、绿色的、连续的过程，用于在室温下直接从水溶液中生物矿化纳米颗粒，并创建用于汽车和其他工业应用的结构化催化剂。生物矿化是生物系统产生无机矿物的过程，无机矿物显示出否则很难实现的纳米结构特征。纳米结构矿物是许多工业重要工艺和产品的重要组成部分，其中对颗粒大小的控制是性能的关键。例如，某些纳米结构矿物，如氧化铈，被用于汽车尾气控制，以消除一氧化碳和其他对环境有害的废气。目前用于生产纳米结构氧化铈的工业方法通常需要高温、高压和有毒溶剂，因此限制了它们的应用。这项研究项目包括研究通过工程酶作为生物催化剂来克服这些限制的方法，用于大规模生产纳米结构CeO2。该项目的研究人员与工业合作伙伴Cerion的研究人员合作，了解工业规模的生产问题。该项目为美国研究生和本科生提供了一个独特的跨学科教育机会，以获得合成生物学、纳米颗粒制造和催化方面的培训。它还提供了与加的夫催化研究所等领先的国际机构合作的机会，这将使美国学生能够学习最先进的生产和表征方法。该项目将导致一种新的、环保的工艺来生产高价值材料，并在汽车等消费品中展示其增强的性能。本研究的目标是开发一种健壮、绿色和灵活的平台，用于在室温下直接从水溶液中高产率地合成尺寸可控的CeO_2和CeO_2O_2纳米粒子，并将这些材料集成到结构化催化剂平台中。该方法是研究和开发工程硅酸盐，负责海绵中二氧化硅矿化的酶，以控制在小于2纳米的尺寸范围内的CeO_2和CeO_2O_2的矿化，与传统的化学合成的纳米CeO_3相比，在初级催化应用中具有功能优势。这些材料的可伸缩、绿色纳米制造的根本技术障碍是通过在工程酶中使用定向进化来提高纳米陶瓷的合成速度，并将它们整合到固定化酶生物催化剂中以用于大规模纳米陶瓷生产。生物矿化的独特优势使得能够合成更小、更均匀的纳米颗粒，并在结构化支撑材料上直接、酶促合成纳米材料，以便将其整合到催化纳米系统中。最终，直接从水溶液中生产纳米氧化钙并控制颗粒尺寸的能力将创造出这些重要的新一代新兴纳米材料的下一代，其成本和规模与工业需求相适应。

This research project seeks to create a scalable, green, continuous process for biomineralization of nanoparticles directly from aqueous solutions at room temperature and to create structured catalysts for automotive and other industrial applications. Biomineralization is the process by which biological systems produce inorganic minerals, which display nanostructured features that are otherwise difficult to achieve. Nanostructured minerals are essential components in a number of industrially-important processes and products, in which control over the particle size is key to performance. As one example, certain nanostructured minerals, such as ceria, are used in automobile emission control, to remove carbon monoxide and other environmentally harmful exhaust gases. Current industrial methods for nanostructured ceria production often require high temperatures, high pressures and toxic solvents, thus limiting their utility. This research project involves studying methods to overcome these limitations by engineering enzymes as biocatalysts for the large-scale production of nanostructured ceria. The researchers on this project collaborate with researchers at Cerion, an industrial partner, to understand industrial-scale production issues. This project provides a unique, cross-disciplinary educational opportunity for U.S. graduate and undergraduate students to gain training in synthetic biology, nanoparticle manufacturing and catalysis. It also provides opportunities to partner with leading international institutes such as the Cardiff Catalysis Institute which will enable U.S. students to learn state-of-the-art production and characterization methods. This project will lead to a new, environmentally-friendly process to produce high-value materials and demonstrate their enhanced performance in consumer products such as automobiles. The goal of this research is to develop a robust, green and flexible platform for the high-yield enzymatic synthesis of size-controlled ceria and ceria-zirconia nanoparticles directly from aqueous solutions at room temperature, and to integrate these materials into structured catalyst platforms. The approach is to study and develop engineered silicatein, the enzyme responsible for silica mineralization in sea sponges, to control mineralization of both ceria and ceria-zirconia in a size range, less than 2 nm, that enables functional superiority in primary catalytic applications as compared to conventional chemically-synthesized nanoceria. The fundamental technical barriers to scalable, green nanomanufacturing of these materials are overcome by using directed evolution in engineering enzymes with enhanced nanoceria synthesis rates and integrating them into immobilized enzyme biocatalysts for large-scale nanoceria production. The unique advantages of biomineralization enables the synthesis of smaller, more homogeneous nanoparticles and the direct, enzymatic synthesis of nanomaterials on structured support materials for their integration into catalytic nanosystems. Ultimately, the ability to produce nanoceria directly from aqueous solutions and to control particle size will create the next generation of these important classes of new, emergent nanomaterials at a cost and scale compatible with the needs of industry.