Exploring Metal Nanocluster Catalysts for Ammonia Synthesis Using Informatics Methods: A Concerted Effort of Bayesian Optimization, Swarm Intelligence, and First-Principles Computation

Abstract

This paper details the use of computational and informatics methods to design metal nanocluster catalysts for efficient ammonia synthesis. Three main problems are tackled: defining a measure of catalytic activity, choosing the best candidate from a large number of possibilities, and identifying the thermodynamically stable cluster catalyst structure. First-principles calculations, Bayesian optimization, and particle swarm optimization are used to obtain a Ti 8 nanocluster as a catalyst candidate. The N 2 adsorption structure on Ti 8 indicates substantial activation of the N 2 molecule, while the NH 3 adsorption structure suggests that NH 3 is likely to undergo easy desorption. The study also reveals several cluster catalyst candidates that break the general trade-off that surfaces that strongly adsorb reactants also strongly adsorb products.

Molecular Understanding of the Distinction between Adhesive Failure and Cohesive Failure in Adhesive Bonds with Epoxy Resin Adhesives

“…In many theoretical studies using periodic DFT, it is assumed that no interaction works between atoms more than 15 Å apart. 27 Therefore, it is unlikely that atoms in the silicon wafer in Figure 1c would affect the adhesion strength of the epoxy resin to the SAM surface. That is why we decided not to include the silicon wafer surface in our model for the DFT calculations.…”

“…The thickness of the SAM made from undecyltrichlorosilane is estimated to be about 15 Å. In many theoretical studies using periodic DFT, it is assumed that no interaction works between atoms more than 15 Å apart . Therefore, it is unlikely that atoms in the silicon wafer in Figure c would affect the adhesion strength of the epoxy resin to the SAM surface.…”