posted on 2023-11-17, 16:37authored byRyan T. Hannagan, Ho Yi Lam, Romain Réocreux, Yicheng Wang, Andrew Dunbar, Vinita Lal, Volkan Çınar, Yunfan Chen, Prashant Deshlahra, Michail Stamatakis, Nathaniel M. Eagan, E. Charles H. Sykes
The identification of thermodynamic
descriptors of catalytic
performance
is essential for the rational design of heterogeneous catalysts. Here,
we investigate how spillover energy, a descriptor quantifying whether
intermediates are more stable at the dopant or host metal sites, can
be used to design single-atom alloys (SAAs) for formic acid dehydrogenation.
Using theoretical calculations, we identify NiCu as a SAA with favorable
spillover energy and demonstrate that formate intermediates produced
after the initial O–H activation are more stable at Ni sites
where rate-determining C–H activation occurs. Surface science
experiments demonstrated that NiCu(111) SAAs are more reactive than
Cu(111) while they still follow the formate reaction pathway. However,
reactor studies of silica-supported NiCu SAA nanoparticles showed
only a modest improvement over Cu resulting from surface coverage
effects. Overall, this study demonstrates the potential of engineering
SAAs using spillover energy as a design parameter and highlights the
importance of adsorbate–adsorbate interactions under steady-state
operation.