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INFEWS N/P/H2O: Photo-thermal ammonia synthesis of plasmonic metal nanoparticles

INFEWS N/P/H2O：等离子体金属纳米粒子的光热氨合成

基本信息

批准号：
1702471
负责人：
Suljo Linic
金额：
$ 30万
依托单位：
Regents of the University of Michigan - Ann Arbor
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2017
资助国家：
美国
起止时间：
2017-09-01 至 2021-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1702471&HistoricalAwards=false
关键词：
INFEWS H2O Photo thermal ammonia

项目摘要

The project investigates a low-temperature, low-pressure photocatalytic alternative to the high temperature and pressure thermo-catalytic Haber-Bosch (H-B) commercial process for ammonia (NH3) production. Ammonia is a primary feedstock for fertilizer production, and its synthesis via the H-B process accounts for 1-2% of global energy consumption. The project will investigate a class of plasmonic metal particles as catalysts for activating the direct, gas-phase synthesis of NH3 from nitrogen (N2) and hydrogen (H2) at low temperatures and pressures utilizing natural ultra-violet and visible light. Photocatalytic synthesis of NH3 thus helps enable a future sustainable-energy path to meet global food needs based on harvesting energy from the sun rather than hydrocarbon resources. The project is built on the hypothesis that plasmonic metal nanoparticles can activate direct, gas-phase ammonia synthesis at low temperatures and pressures when illuminated by UV-vis light of solar intensity. The defining characteristic of plasmonic metallic nanostructures is their strong resonant interaction with UV-vis light through the excitation of localized surface plasmon resonance (LSPR) which results in high rates of formation of high-energy electrons at the surface of the nanoparticles. The energetic electrons can induce chemical reactions on metals, including the activation of strong chemical bonds at low temperatures. The project will seek to enhance the plasmonic effect for NH3 synthesis by utilizing core-shell particles with a plasmonic metal core (Au, or Ag) and a thin shell (or even a small cluster) of a chemically more active metal (Ru, Rh, Pt, Pd, etc.). In the proposed bimetallic systems, the role of the plasmonic core is to efficiently harvest the energy of light and transfer it in the form of energetic electrons to the more active material. The role of the more active metal is to provide the catalytic sites for binding and dissociation of N2 using the energetic electrons. Further reduction of the N and NHx intermediates is fast on these metals. Beyond NH3 synthesis, the project will address a number of fundamental questions about the interaction of local light-induced electric fields on plasmonic metals and adsorbates. These questions are critical for controlling the hot-electron flow at nanoscales, which is of importance in the fields of photochemistry, photovoltaics and any application where photo-excitation and energetic charge harvesting play a role. The project will also employ a number of educational and outreach activities designed to promote learning via trickle-down of research findings through the curriculum to graduate, undergraduate, and even younger students while also involving a diverse group of younger students in conventional outreach programs and less conventional strategies aimed at improving the utilization of the World Wide Web in reaching students and the general public.

该项目研究了一种低温低压光催化替代高温高压热催化Haber-Bosch（H-B）氨（NH3）生产商业工艺。氨是化肥生产的主要原料，通过H-B工艺合成的氨占全球能源消耗的1-2%。该项目将研究一类等离子体金属颗粒作为催化剂，用于利用自然紫外线和可见光在低温和低压下激活由氮气（N2）和氢气（H2）直接气相合成NH3。因此，NH3的光催化合成有助于实现未来的可持续能源路径，以满足全球粮食需求，其基础是从太阳而不是碳氢化合物资源中获取能量。该项目是建立在假设等离子体金属纳米粒子可以激活直接，气相氨合成在低温和低压时，由太阳强度的紫外可见光照射。等离子体金属纳米结构的定义特征是它们通过局部表面等离子体共振（LSPR）的激发与UV-可见光的强共振相互作用，这导致在纳米颗粒表面处形成高能量电子的高速率。高能电子可以在金属上引发化学反应，包括在低温下激活强化学键。该项目将寻求通过利用具有等离子体金属核（Au或Ag）和化学上更活跃的金属（Ru、Rh、Pt、Pd等）的薄壳（或甚至小簇）的核-壳颗粒来增强用于NH3合成的等离子体效应。在所提出的电子束系统中，等离子体核心的作用是有效地收集光能，并将其以高能电子的形式转移到更活跃的材料中。活性更高的金属的作用是为N2的结合和解离提供催化位点。N和NHx中间体的进一步还原在这些金属上是快速的。除了NH3合成，该项目还将解决一些关于等离子体金属和吸附物上局部光致电场相互作用的基本问题。这些问题对于控制纳米尺度下的热电子流至关重要，这在光化学、光化学和任何光激发和高能电荷捕获发挥作用的应用领域都很重要。该项目还将采用一些教育和推广活动，旨在促进学习，通过涓滴的研究成果，通过课程研究生，本科生，甚至年轻的学生，同时也涉及一个不同的年轻学生群体在传统的推广计划和不太传统的战略，旨在提高利用万维网在达到学生和公众。