Electronic Communication Between Ferroelectric Surface Dipoles and Catalytic Active Sites Under Diverse Reaction Conditions

Abstract Dynamic modulation of the electronic environment of catalytic active sites offers a promising route to overcome the limitations of static catalyst design. One possible direction to achieve this goal is to induce catalyst dynamics via rapid inversion of the surface dipole of a ferroelectric catalyst; however, the potential scope of electronic coupling between active sites and ferroelectric surface dipoles is not clear. Herein, we investigate whether ferroelectric supports can electronically communicate with supported transition-metal sites under a variety of catalytic conditions and across chemically distinct reaction environments. BaTiO3 and NaNbO3 were employed as representative ferroelectric supports and functionalized by surface organometallic chemistry with Ru, Ni, Pt, and V molecular precursors. The key probe employed to evaluate dipole-active-site coupling is the inspection of spectroscopic features and reaction energetics above and below the Curie temperature (Tc) of the material, in order to establish if the collapse of the ferroelectric dipole at Tc results in a discrete discontinuity in these temperature-dependent metrics. The influence of ferroelectric phase transitions on active-site electronics and reactivity was probed through in situ CO adsorption DRIFTS measurements and through kinetic analysis of CO oxidation, NH3 reforming, and ethylene hydrogenation. In situ DRIFTS of CO adsorbed on Ru/BaTiO3 and Pt/BaTiO3 revealed discontinuous changes in carbonyl band intensities and frequencies near the Curie temperature of BaTiO3, consistent with changes in the metal electronic structure induced by the support-phase transition. Across all three probe reactions, Arrhenius analysis reflects discontinuities in apparent activation barriers at the Tc of BaTiO3 and NaNbO3, indicating that the discrete change in surface polarization at the phase transitions measurably alter catalytic reaction energetics. For Ni/BaTiO3, in situ Ni K-edge X-ray absorption spectroscopy further shows reversible spectral changes above and below the Tc, reflecting persistent electronic coupling between supported Ni sites and the ferroelectric surface under reducing conditions. These findings demonstrate the promise of ferroelectric supports as platforms for dynamically tunable heterogeneous catalysis, further motivating future reactor and materials design that may enable active switching of catalyst polarization under working conditions.