(621ak) Fundamental Insights into the Connection Between Homogeneous and Heterogeneous Catalysts Via DFT Analyses

Authors: 
Praserthdam, S., Texas A&M University
Balbuena, P. B., Texas A&M University

Catalysts are quintessential parts in chemical industries, especially heterogeneous catalysts. Both homogeneous and heterogeneous catalysts are efficiently used in many processes, and each of them has its unique benefits and drawbacks. Although homogeneous catalysts have been well recognized because of their greater interaction with reactants which promotes reaction rate, they are often irrecoverable after the reaction, while heterogeneous catalysts can be recovered with ease after used [1].

In this work we investigate connections between homogeneous and heterogeneous catalysts and provide general criteria toward the design of catalysts combining the benefits of each approach. Our analyses are based on first principles computational techniques such as density functional theory (DFT) and ab initio molecular dynamics (AIMD) simulations. For heterogeneous catalysts, employing an optimal size of active site can be beneficial, e.g., the use of Iron single-site embedded in silica matrix support can selectively convert methane to ethylene, while suppressing coke formation [2]. Thus, discovering the optimal conditions (size, interactions with support, oxidation state) for heterogeneous catalysts to begin exhibiting favorable homogeneous catalyst’s behavior, e.g., enhancement of surface interaction with reactants would be a great foundation toward a proper design of highly active heterogeneous catalysts.

References

[1] Nørskov, Jens K. (2014). Fundamental Concepts in Heterogeneous Catalysis. Hoboken, New Jersey: John Wiley & Sons

[2] Guo, X. et al, Science, 2014, 344, 616-619.