The high activity and selectivity of Fe-based heterogenous catalysts toward a variety of reactions that require the breaking of strong bonds is offset in large part by their exceptional instability toward oxidative deactivation. While it has been shown that the stability of Fe catalysts is considerably enhanced by doping them with precious metals (even at the single-atom limit), rational design criteria for choosing such dopants are still missing. Since oxidative deactivation occurs due to the strong binding of oxygen to Fe, and reduction by adsorbed hydrogen mitigates the deactivation, we propose here to use the binding affinity of oxygen and hydrogen adatoms as the basis for rational design. As it would also be beneficial to use cheaper metal dopants, we have scanned over a large subset of 3d – 5d mid-to-late transition metal dopants and computationally determined their effect on the oxygen and hydrogen adlayer binding as a function of chemical potential and adsorbate coverage. We further determine the underlying chemical origins that are responsible for these effects and connect them to experimentally tunable quantities. Our results reveal a reliable periodic trend wherein oxygen binding is weakened greatest as one moves right and down the periodic table. Hydrogen binding shows the same trend only at high (but relevant) coverages, and otherwise tends to have its binding slightly increased in all systems. Trends with dopant coverage are also uncovered and connected to experimentally tunable parameters.

Guiding surface modification of single atom alloy Fe(100) with insights from configurational space: Adsorption of hydrogen and oxygen on M<sub>1</sub>Fe(100)

ACS Spring Meeting 2021

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Guiding surface modification of single atom alloy Fe(100) with insights from configurational space: Adsorption of hydrogen and oxygen on M1Fe(100)

Guiding surface modification of single atom alloy Fe(100) with insights from configurational space: Adsorption of hydrogen and oxygen on M₁Fe(100)