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

丙烯直接氧化为环氧丙烷代表了改变为更可持续地生产分子的巨大潜力，目前该分子的生产水平为每年90亿磅。目前的生产本质上是低效的，使用大量的能源并产生大量的浪费。本工作提出了新的催化剂组合物和高度工程化的结构，有可能促进直接氧化与分子氧在改善的选择性和转化率，并与较少的能源消耗和环境waste.The PI假设，丙烯选择性氧化的稳定性，选择性和效率可以通过仔细合成Pd-Au和Ag-Au纳米催化剂提高。预期新催化剂受益于Au的高选择性和附加的第二金属的高活性。 Au纳米团簇用Pd或Ag的表面原子装饰，并且所得颗粒彼此隔离并且通过在颗粒之间沉积金属氧化物小丘而优化用于与钛-硅沸石载体的相互作用。 胶体合成和原子层沉积（ALD）的结合将用于创建高度工程化的结构。 同步辐射X射线吸收精细结构（XAFS）光谱和原子尺度的动力学蒙特卡罗（KMC）计算将被用来揭示工作催化剂的动态图像，并精确地识别第二金属的机械作用。 如果成功，这些催化剂可能会改变环氧丙烷行业的游戏规则。 此外，该研究将为此类双金属催化剂在其他大规模工业化学反应中的潜在作用提供有价值的理解。 这项研究将通过为亚拉巴马州两所机构的两名研究生和本科生提供支持来实现教育推广。 另一个外展组成部分是由本科生和研究生研究人员实地考察催化剂生产基地和商业研发中心在亨茨维尔地区。

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.