UNS:Collaborative Research: Atomistic Design of High-Performance Epoxidation Catalysts with Atomic Layer Deposition and Kinetic Monte Carlo Simulations

University Of Alabama Tuscaloosa, Tuscaloosa AL

Investigators

Abstract

1511820(Lei) & 1510485(Turner) Direct oxidation of propylene to propylene oxide represents huge potential for a change to much more sustainable production of a molecule that currently has production levels of 9 billion pounds a year. Current production is inherently inefficient using vast amounts of energy and producing significant waste. This work proposes novel catalyst compositions and highly-engineered structures that have the potential to promote the direct oxidation with molecular oxygen at improved selectivity and conversion, and with less energy consumption and environmental waste. The PIs hypothesize that the stability, selectivity, and efficiency of propylene selective oxidation can be improved by carefully synthesizing Pd-Au and Ag-Au bimetallic nano-catalysts. The new catalysts are expected to benefit from the high selectivity of Au and the high activity of the additional second metal. Au nanoclusters are decorated with surface atoms of Pd or Ag, and the resultant particles are isolated from one another and optimized for interaction with a titanium-silicalite support by the deposition of metal oxide hillocks between the particles. The combination of colloidal synthesis and atomic layer deposition (ALD) will be used to create the highly-engineered structures. Synchrotron X-ray absorption fine structure (XAFS) spectroscopy, and atomic-scale kinetic Monte Carlo (KMC) calculations will be employed to potentially reveal a dynamic picture of the working catalysts and precisely identify the mechanistic role of the second metal. If successful, these catalysts could be a a game-changer for the propylene oxide industry. In addition the study will provide valuable understanding of the potential role of bimetaliic catalysts of this type for other large-scale industrial chemical reactions. The study will achieve educational outreach by providing support to two graduate students and also undergraduate students at two institutions within the state of Alabama. Another outreach component is field trips by both undergraduate and graduate researchers to catalyst manufacturing sites and commercial R&D centers in the Huntsville area.