(5c) Programmable Catalysts Control Reaction Selectivity Via Kinetics

Higher-performance catalysts are necessary for widespread adaptation of renewable sources of energy and chemicals. As an alternative to the current paradigm of breaking linear scaling relationships (LSRs), we propose the addition of a temporal component to catalyst design via programmable catalysts.^[1] Application of an external stimulus reversibly tunes the properties of programmable catalysts, providing a mechanism for temporal optimization to elementary reaction kinetics during dynamic operation. Dynamic turnover enhancement has been demonstrated in microkinetic analyses^[2,3]and experimental studies,^[4] however dynamic selectivity control remains less explored. Herein, we discuss how programmable catalysts with LSR slopes < 0 can be leveraged to offer near-complete selectivity control of a model A-to-B reaction.^[5]

Dynamic catalysis was simulated for a thermoneutral A-to-B catalytic, reversible reaction using method established in [2]. To elucidate how programmable catalysts can be optimized to control reaction selectivity, we varied the waveform amplitude and frequency of the applied stimulus, which can easily be tuned in the lab, and the catalyst-chemistry-stimulus pairing’s properties, which were parameterized into two LSRs. We found that the steady-state batch reactor composition varied from 0 to 100 mol% B; the LSR slopes parameterizing the catalyst-chemistry-stimulus pairings featured the strongest correlation with the composition. Additionally, we developed a directionality descriptor, ل, that can be used a priori to predict the reaction direction that will be promoted at dynamic steady state.

The findings of this study demonstrate that programmable catalysts exhibit significant control of reaction selectivity, and we propose a robust descriptor, Ù„, that can be used as a screening tool when investigating different catalyst-chemistry-stimulus pairings for specific reactions.

[1] ACS Catal. 2020, 10(21), 12666.

[2] ACS Catal. 2019, 9(8), 6929.

[3] Sci. Adv. 2022, 8(4), eabl6567.

[4] ACS Catal. 2020, 10(17), 9932.

[5] Chem Catalysis 2022, 2(1), 140.