The Catalytic Mechanics of Dynamic Surfaces: Stimulating Methods for Promoting Catalytic Resonance

Abstract

Transformational catalytic performance in rate and selectivity is obtainable through catalysts that change on the time scale of catalytic turnover frequency. In this work, dynamic catalysts are defined in the context and history of forced and passive dynamic chemical systems, with classification of unique catalyst behaviors based on temporally-relevant linear scaling parameters. The conditions leading to catalytic rate and selectivity enhancement are described as modifying the local electronic or steric environment of the active site to independently accelerate sequential elementary steps of an overall catalytic cycle. These concepts are related to physical systems and devices that stimulate a catalyst using light, vibrations, strain, and electronic manipulations including electrocatalysis, back-gating of catalyst surfaces, and introduction of surface electric fields via solid electrolytes and ferroelectrics. These catalytic stimuli are then compared for capability to improve catalysis across some of the most important chemical challenges for energy, materials, and sustainability.

Identifying a New Pathway for Nitrogen Reduction Reaction on Fe-Doped MoS2 by the Coadsorption of Hydrogen and N2

“…The blocking of the V S @1Fe-S50 site by H might play a role in the low NRR selectivity of Fedoped MoS 2 catalysts at large cathodic potentials reported in recent experiments. 22,29,30 Based on our results, it seems possible that NRR, using Fe-doped MoS 2 catalysts, may benefit from potential cycling approaches 61,62 to selectively favor N 2 adsorption at low potentials and, thereafter, drive the reduction of *N 2 at higher potentials. 3.5.1.1.…”

Catalytic Resonance of Ammonia Synthesis by Dynamic Ruthenium Crystal Strain

“…The dynamic strain results in a periodic conversion differing from equilibrium, consistent with other dynamic ratcheted systems. (21,57) In Figure 6A, the ammonia synthesis reaction was simulated in a batch reactor at 320 ⁰C and 20 atm starting with a stoichiometric mixture of H 2 and N 2 gases. Initial static catalysis proceeds to 33% conversion at equilibrium, after which dynamic strain (± 4%) at varying frequency (5, 10, 15, and 20 kHz) was imposed.…”

“…As recently described via simulation, (19,20) oscillation of the catalyst electronic state between sides of the Sabatier peak can accelerate the overall reaction rate, control the extent of reaction, and even select specific reaction pathways in a reaction network. (21,22) These dynamic catalysts exhibit a band of resonant applied frequencies yielding the highest catalytic turnover frequency unique to each catalytic reaction. Dynamic catalytic rate acceleration has already been demonstrated with dynamic formic acid electro-oxidation(23) and dynamic photocatalysis for methanol decomposition.…”

Coverage-dependent formic acid oxidation reaction kinetics determined by oscillating potentials

“…It was further predicted that oscillations need to be in approximate resonance with the surface reactions to achieve reaction enhancements. [9][10][11][12] DFT calculations by Shetty et al revealed electric field-dependent linear scaling relationships of adsorbates on metal surfaces imperative for the understanding of dynamic catalytic processes. 13 Cycling between a potential suitable for the non-Faradaic dehydration of FA to surfaceadsorbed CO and the Faradaic oxidative desorption to form CO 2 enhanced the activity by a factor of up to around 20 at frequencies of 100 Hz, 14 consistent with promotional effect observed by Adžić et al earlier.…”