Selective CO hydrogenation over bimetallic nanoparticles
Abstract
CO2 hydrogenation and Fisher-Tropsch synthesis (FTS) are both desirable pathways to produce synthetic chemicals and fuels via low-co challenge in the field of catalysis. Our research team will utilize expertise in synthesis, characterization, density functional theory (DFT) calculations and machine learning to develop a framework for synthesizing highly active catalysts for selectively hydrogenating CO in CO/CO2 mixtures for use by the U.S. Navy and Department of Defense (DoD). Our research team has recently achieved success in collaboration with the Naval Research Laboratory (NRL) in developing a highly selective K-Mo2C reverse water-gas shift (RWGS)catalyst as an integral component for the seawater to fuel process. The effluent CO from RWGS can be further hydrogenated into fuels via Fischer-Tropsch synthesis. To ensure scalability and implementation of the seawater to fuel process, it is necessary to characterize and exploit the physicochemical interactions within FTS catalysts to control the effluent hydrocarbon fractions produced from CO/CO2 mixtures.To achieve our goal of tuning hydrocarbon selectivity during hydrogenation of CO/CO2 mixtures, we plan to design, synthesize and test bimetallic zeolite-based catalysts that selectively hydrogenate CO to form olefins and/or heavier hydrocarbons for fuels. Bimetallic catalysts exhibit distinct electronic and structure properties from either parent metal. These bimetallic catalysts result in enhanced activity, selectivity and stability, using earth abundant elements while avoiding expensive and rare precious metals. The zeolite support is highly tunable, allowing us to control the acid-base properties to stabilize the desired bimetallic active phase, and in turn, CO/CO2 hydrogenation performance. To test our hypothesis, we plan to identify catalyst descriptors topredict selective CO hydrogenation in a mixture of CO and CO2, thereby kinetically limiting the undesired RWGS and Sabats. Upon identification of promising bimetallics, support acid-base properties will be tested for controlling reaction selectivity. The nanoparticles will then be deposited onto the oxide supports to determine the structure of the active phase in situ and elucidate the reaction mechanism. In addition to our targeted approach for selective catalyst design, we also plan to investigate the existing Co-Ru catalyst in mixed CO/CO2 streams at the molecular and laboratory scales. Obtaining data on the performance of the Co-Ru control catalyst at the molecular, laboratory and pilot-scales will allow us to predict how our novel bimetallic catalyst formulations will perform in the pilot-scale modular reactor. This well-integrated computational/experimental approach will result in significanttime, energy and cost savings, as we study other catalyst candidates for the scaled-up process.These control experiments are essential for the design of an integrated, modular system, and enable the implementation of the seawater to fuel process.The proposed work is an integral part of an advanced energy conversion platform of the U.S. Navy to synthesize fuel from seawater with increased energy efficiency and safety. We expect the Co-based bimetallic catalysts under development in the proposed work to achieve increased selectivity and reduced operating temperatures, and be used in the modular system to synthesize fuel from seawater. Within this mission, our project understands the potential for seabed energy harvesting by developing advanced catalytic materials, and introducing novel chemical conversion approaches, resulting in a cost-effective, highly efficient and environmentally-sound deployment.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Apr 06, 2021
- Source ID
- N000142112246
Entities
People
- Marc D Porosoff
Organizations
- Office of Naval Research
- United States Navy
- University of Rochester