(82b) First-Principles Modeling of the Effect of Surface Modification Strategies on Hydrogenation Catalysis

Common methods to tune the performance of heterogenous transition metal catalysts include combining two or more metals to form an alloy, synthesizing shape- or size-specific nanoparticles, and utilizing a catalyst support to impart bifunctionality. In addition, but less widely applied, the surface of a transition metal catalyst can be tailored through controlled monolayer deposition of organic or inorganic surface modifiers. Here, two recent examples of surface modification of Pd, leading to enhanced hydrogenation activity, will be discussed. In the first example, a partial monolayer TiO₂ overcoat deposited on Pd via atomic layer deposition is found to modulate the relative binding strength of surface intermediates in naphthalene hydrogenation leading to an increase in turnover frequency relative to the uncoated Pd catalyst.¹ In a second example, the addition of organic phosphonic acid (PA) modifiers to Pd is shown to enhance ring hydrogenation of furfural alcohol through hydrogen-bonding interactions between the surface bound intermediates and the PA modifiers.² For both of the examples discussed, the unexpected hydrogenation activity enhancement resulting from addition of the surface modifier to Pd is revealed through first-principles atomic-scale modeling of the underlying surface chemistry.

1. W. W. McNeary, S. A. Tacey, G. Lahti, D. R. Conklin, K. A. Unocic, E. C. D. Tan, E. C. Wegener, T. E. Erden, S. Moulton, C. Gump, J. Burger, M. B. Griffin, C. A. Farberow, M. J. Watson, L. Tuxworth, K. M. Van Allsburg, A. A. Dameron, K. Buechler, D. R Vardon, ACS Catalysis (2021) – in press.
2. P. Coan, C. A. Farberow, M. B. Griffin, J. W. Medlin, ACS Catalysis 11, 3730 (2021).