DEVELOPING AND VALIDATING SUB-NANO CATALYSTS FOR ENDOTHERMIC COOLING
Abstract
The goals and objectives of the proposed research are in the area of endothermic fuel reactions, with application to powered hypersonic flight. The work is motivated by the need to selectively catalyze endothermic reactions in fuels, thus enhancing the fuel cooling capacity, while minimizing formation of carbon deposits (coking), which tend to clog fuel passages, leading to system failure. We will focus on catalysts consisting of sub-nano clusters deposited on oxide supports as highly active, and metals efficient catalysts. Specifically, we will investigate tuning the activity, selectivity, and thermal stability of the catalysts by size-selection, alloying of the clusters, and doping the support. All these factors have been shown to affect the electronic and geometric structure of the catalyst clusters, changing the energetics for reactions, and anchoring the clusters to the support. Understanding how to optimize these multi-component catalysts requires tightly coupled, and mutually reinforcing theory and experiments, to predict, prepare, and study well-defined cluster catalysts. The PIs have developed many tools and methods required for this purpose. The experiments will take advantage of a new DURIP-funded microreactor capability what will allow cluster catalysis to be studied at high pressures and high temperatures. The theory includes unique methods developed under previous AFOSR grants to describe fluxional cluster catalysts as statistical ensembles of isomers, leading to a new paradigm in catalyst description and design. Theory extensively uses the DoD HPC resources. One of the objectives for this work is to develop new knowledge about the detailed mechanisms of reactions at high temperatures and reactant loadings (i.e., high pressures), including the effects of thermal and adsorbate-driven evolution of the catalysts. Another objective is to develop new approaches to understanding catalyst deactivation by coking, sintering, or other catalyst particle morphological changes, and how to prevent it. Achievement of these objectives will enable development of new catalysts with improved activity, selectivity, and stability for endothermic fuel cooling. Finally, the methods and design principles emerging from this work will be significant in a broader range of catalytic applications, including processes of interest for synthetic fuel production such as steam reforming and Fischer –Tropsch synthesis.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Apr 20, 2023
- Source ID
- FA95502210381
Entities
People
- Anastassia N. Alexandrova
Organizations
- Air Force Office of Scientific Research
- United States Air Force
- University of California, Los Angeles