Title: Towards Rational Design of Liquid Metal Catalyst Solutions as a Novel Reaction Medium for Light Alkane Dehydrogenation

Abstract:

Olefins serve as key chemical precursors, ubiquitous in numerous consumer commodities, ranging from plastics to pharmaceuticals. While non-catalytic steam cracking remains the cornerstone of industrial olefin synthesis, it remains afflicted as a substantial energy sink and a significant source of carbon emissions. This stems from the combined effect of severe cracking temperatures, incorporation of high-pressure steam needed to suppress coke formation, and flue gas generated from fuel combustion necessary to provide sufficient duty to the cracking furnace and regular decoking of reactor components. Catalytic processes such alkane dehydrogenation tap into the abundance of alkanes in shale gas and offers an alternative path to meet the growing global demand of olefins. However, this process employs conventional solid catalysts that persistently suffer from catalyst deactivation due to coking, hampering their long-term efficacy and stability. Emerging as a promising solution to catalyst instability, the concept of liquid metal catalysis capitalizes on intrinsic differences in density to separate coke from the dynamic, liquid metal solution. This unique feature offers a transformative advantage, preventing coking deactivation and ensuring prolonged catalyst activity. Building upon this, this proposal aims to investigate the intricacies that underpin liquid metal behavior and their practical application in catalytic, chemical processes such as alkane dehydrogenation.

Specifically, we focus on three key aims:

Aim 1. Design strategies for well-defined liquid bimetallic catalysts: Our first objective centers on design approaches to realizing well-defined liquid metal catalyst materials with uniformly dispersed compositions, thus ensuring homogeneity of the liquid metal catalyst solution.

Aim 2. Screening for active, bimetallic combinations of liquid metals for alkane dehydrogenation: Building on the previous aim, we will conduct thorough screenings to identify optimal bimetallic combinations of liquid metals that afford high catalytic activity and selectivity for alkane dehydrogenation. We aim to uncover synergistic effects between different liquid metal species, enhancing overall catalytic performance.

Aim 3. Supported liquid metal catalysts to evaluate robustness against coking: Finally, we propose using supported liquid metal catalysts as a platform to assess the robustness and catalytic stability of liquid metal catalysts compared to conventional solid state-of-the-art catalysts. By conducting side-by-side comparisons, we seek to demonstrate the advantages of liquid metal catalysis in terms of longevity and performance.

Through these objectives, our research seeks to advance the field of olefin production, one of the chemical processes that leveraging the unique properties of liquid metal catalysts, is poised to improve. Liquid metal catalysis is a nascent concept, but its successful exploitation could yield significant benefits for the catalysis community, paving the way for more sustainable and efficient processes in the future.

Chair:

Dr. Mohammad Masnadi

Department of Chemical and Petroleum Engineering, University of Pittsburgh

Committee:

Dr. Giannis Mpourmpakis

Department of Chemical and Petroleum Engineering, University of Pittsburgh

Dr. Götz Veser

Department of Chemical and Petroleum Engineering, University of Pittsburgh

Dr. Wei Xiong

Department of Mechanical and Materials Science Engineering, University of Pittsburgh