Ultrashort Pulse Laser for Research on Deposition and Desorption dynamics of Jet Fuel Pyrolysis Products
Abstract
Endothermic hydrocarbon fuels are extensively studied for their application in hypersonics- their chemistries and chemical dynamics are a topic of intense interest. Following combustion, this type of fuel produces a variety of smaller carbon-based chemicals that can deposit on surfaces and polymerize, a process known as coking. Coking is a universal problem that plagues virtually all technologies that rely on hydrocarbon combustion- it is a process of concern for land, sea, and air-based engines, and as such, is an ongoing challenge for the Department of Defense. Coking is the buildup of unwanted carbon deposits which can block critical components and ultimately result in engine failure. In the chemical industry, where chemical reactions using hydrocarbon feedstock are typically run at high temperatures and assisted by a catalyst, coking is a major limiting factor in catalyst lifetime. Over the past several years the Halas group has been studying and advancing light-based chemistries by developing Plasmonic Photocatalysts- these are specially designed, optically active metal nanoparticle complexes with engineered reactive sites that are used to drive chemical reactions. This basic research into the underlying science behind plasmonic photocatalysis has led to a rapid commercialization of this new type of chemistry, currently in multiple field trials for low-cost, electrically driven Hydrogen production. In this context, the Halas group has observed that residual product deposition- coking in the case of hydrocarbon reactions- on plasmonic photocatalyst surfaces is greatly reduced in comparison with thermocatalyst surfaces. This drastic reduction in residual product deposition can be directly attributed to a light-induced desorption process at the photocatalyst surface. The rationale behind this equipment request is to more comprehensively investigate the plasmon-induced desorption process, particularly for the case of small carbon molecule combustion products. Our plan is to focus our studies on the deposition and desorption dynamics of small molecules known to be the products of jet fuel pyrolysis. We intend to investigate precisely how nanostructured surfaces can, when illuminated, control and arrest the deposition and actively promote the desorption of several types of small molecules of the types that contribute to coking. These studies should open the door to the design, fabrication and development of new types of light-activated materials and coatings that could prevent or reduce coking in critical applications.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 05, 2025
- Source ID
- FA95502410019
Entities
People
- Naomi J. Halas
Organizations
- Air Force Office of Scientific Research
- Rice University
- United States Air Force