SGER: Thermal Effects in Microwave Enhanced Catalysts

SGER：微波增强催化剂中的热效应

• 批准号: 9907322
• 负责人: James Thomas
• 金额: $ 2.92万
• 依托单位: Virginia Polytechnic Institute and State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-05-01 至 2001-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9907322&HistoricalAwards=false
• 关键词: SGER; Thermal; Effects; Microwave; Enhanced

AbstractCTS-9907322J. Thomas/VPIThis research project is directed toward providing answers to fundamental questions concerning heat production and transport when microwave energy is used to promote chemical reactions on supported metal catalysts. These materials consist of nanometer-sized metallic particles distributed within a porous ceramic substrate. Microwave fields do not couple to the ceramic support at temperatures of interests in chemical reactions, but they may couple strongly to the metallic particles because of electron quantum confinement. This phenomenon offers the opportunity to selectively heat the catalyst particles to temperatures higher than the matrix. Selective heating can result in greater control over chemical reactions and possibly high selectivity for desirable products. Increased selectivity in microwave-enhanced chemical catalysis has been reported, but the causes are unclear. Because of the difficulty of measuring temperatures of nanometer-sized particles, no direct verification of selective heating has yet been achieved. This project will employ theoretical modeling and a novel experimental technique based on neutron absorption to determine whether catalyst particles are susceptible to selective heating by microwaves. Temperature measurement of nanometer-sized particles cannot be done by conventional techniques. Neutron resonance radiography will be used to resolve the temperatures of catalyst particle and support. The success of this method could open a new avenue for developing catalytic reactions.

摘要CTS-9907322J。 Thomas/VPI 该研究项目旨在为使用微波能促进负载型金属催化剂上的化学反应时热量产生和传输的基本问题提供答案。 这些材料由分布在多孔陶瓷基材内的纳米尺寸金属颗粒组成。 在化学反应感兴趣的温度下，微波场不会耦合到陶瓷支撑体，但由于电子量子限制，它们可能会强烈耦合到金属颗粒。 这种现象提供了选择性地将催化剂颗粒加热到高于基质的温度的机会。 选择性加热可以更好地控制化学反应，并可能对所需产物具有高选择性。 据报道，微波增强化学催化的选择性有所提高，但原因尚不清楚。 由于测量纳米尺寸颗粒的温度很困难，目前尚未实现选择性加热的直接验证。 该项目将采用理论模型和基于中子吸收的新颖实验技术来确定催化剂颗粒是否容易受到微波的选择性加热。 传统技术无法测量纳米颗粒的温度。 中子共振射线照相术将用于确定催化剂颗粒和载体的温度。 这种方法的成功可能为开发催化反应开辟一条新途径。