(532dh) Programmable Catalysts Inspired By Semiconductor Devices

Development of higher-performance catalysts is requisite for reducing the carbon footprint of the chemicals industry and implementing distributed production of chemical energy liquids. We propose that programmable catalysts, in which the properties of the active site are temporally tuned to reaction kinetics, is an alternate strategy to the current paradigm of breaking linear scaling relationships through new active site designs.^[1] Our microkinetic analyses have predicted that these programmable catalysts can increase both catalyst activity^[2] and offer significant control of reaction selectivity,^[3] and we have recently fabricated an alumina-graphene programmable catalyst called a catalytic condenser.^[4]

Herein, we will discuss the details of graphene-supported metal oxide catalytic condensers. These devices are based on parallel plate capacitors in which the top plate is made from a catalytically-active material supported on graphene, which distributes charge laterally across the surface and affords greater flexibility in selecting the catalytic material. Applying an electrical bias to the device allows for facile and reversible tuning of the electron density in the catalytic layer, providing a means for temporal control of thermochemical reactions. We will highlight our work showing electrostatic tuning of Lewis acidity in ultrathin (< 10 nm) titania films, which is probed via temperature programmed desorption (TPD) of Lewis basic probe molecules, and discuss how the properties of these ultrathin films relate to the performance of the catalytic condenser.

We anticipate that the programmable catalyst design can be extended to additional catalytic materials and applied to improve catalyst performance in thermo- and electrocatalytic reactions of societal importance.

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

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

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

[4] JACS Au, 2022, in press.