(218e) First-Principles Based Design of Reaction Conditions for the Catalytic Conversion of Methane to Methanol over Cu-Exchanged SSZ-13
AIChE Annual Meeting
2017
2017 Annual Meeting
Computational Molecular Science and Engineering Forum
Faculty Candidates in CoMSEF II: Energy, Catalysis, and Interfaces
Monday, October 30, 2017 - 4:15pm to 4:30pm
In this contribution, we construct a thermodynamic model for Cu in zeolite SSZ-13 based on RPA Density Functional Theory, and show that under almost all conditions the formation of a distribution of CuxOyHz clusters is favorable. We identify the chemical potential of O and H (μO and μH), the local Al distribution, the reference state and the temperature as important parameters in predicting the exact stoichiometry of these sites. We furthermore model the CuxOyHz distribution of several systems studied in the literature; comparing these results to experimental studies for the catalytic conversion of methane to methanol significantly narrows down candidates for the most active sites. In a subsequent step we then use our model to predict conditions, which lead to equally as good or better catalytic performance.
The systematic work presented here shows that the Cu speciation in zeolites is condition-dependent and that there is not one single Cu species present. Furthermore, we establish basic rules for choosing the proper conditions to optimize the performance of this catalytic system.