Cavity Catalysis ‒Accelerating Reactions under Vibrational Strong Coupling‒

In conventional catalysis the reactants interact with specific sites of the catalyst in such a way that the reaction barrier is lowered and the reaction rate is accelerated. Here we take a radically different approach to catalysis by strongly coupling the vibrations of the reactants to the vacuum electromagnetic field of a cavity. To demonstrate the possibility of such cavity catalysis, we have studied hydrolysis reactions under strong coupling of the OH stretching mode of water to a Fabry-Pérot (FP) microfluidic cavity mode. This results in an exceptionally large Rabi splitting energy ℏΩ_R of 92 meV (740 cm⁻¹), indicating the system is in vibrational ultra-strong coupling (V-USC) regime and we have found that it enhances the hydrolysis reaction rate of cyanate ions by 10² times and that of ammonia borane by 10⁴ times. This catalytic ability is shown to depend only upon the cavity tuning and the coupling ratio. Given the vital importance of water for life and human activities, we expect our finding not only offers an unconventional way of controlling chemical reactions by ultra-strong light-matter interactions, but also changes the landscape of chemistry in a fundamental way.