Unraveling Intrinsic Electronic Factors in Thermocatalytic (Hemi-)Hydrogenation of Ethylene and Acetylene with Electric Polarization

Abstract

Favorable electronic interactions between active sites and substrates or transition states are essential to promoting a catalytic reaction. However, tuning the electronic state is often coupled with compositional or structural changes of active sites, leading to uncertainties in the catalyst design. Herein, we isolate the impact of the Fermi level of Pt, Pd, and Rh nanoparticles on thermocatalytic (hemi)hydrogenation of ethylene and acetylene with electric polarization. Through a combination of kinetic, spectroscopic, isotopic labeling, and computational investigations, we show that the electric polarization by applying a potential bias tunes the rate and product distribution of ethylene hydrogenation by altering the coverages of key intermediates, e.g., hydrogen, acetonitrile, and ethylene. The proposed mechanistic framework rationalizes the simultaneous increase in the rate and selectivity of acetylene hydrogenation on Pt as the Fermi level is increased by applying a negative potential bias. This work highlights the promise of leveraging electric polarization as a strategy to advance the mechanistic understanding and optimize performance in heterogeneous catalysis.

CatTestHub: A Benchmarking Database of Experimental Heterogeneous Catalysis for Evaluating Advanced Materials

“…[33][34][35] New catalytic technologies comprised of new material compositions and structures are continuously being introduced, [1][2][3][4] with the goal of outperforming preceding materials. Catalysts are being used in unique systems that combine the surface with non-thermal plasma [36][37][38] or methods of applying charge, 39,40 , electric fields, 41,42 strain, [43][44][45] or light. [46][47][48][49] More recently, these catalyst perturbations are being applied dynamically to achieve even greater enhancements of reaction rate or surface chemistry control.…”