Dynamic electrification steers the selectivity of CO2 hydrogenation

The performance of electrified reactors under dynamic operation can surpass that of conventional steady-state operation. Here, we demonstrate that rapid pulse heating (RPH) operation of the CO2 hydrogenation reaction at 1 bar over a Ni/Al2O3 catalyst increases the reaction rate and shifts the product selectivity toward CO over CH4 at low reaction temperatures (<500 C-o). Operando FTIR characterization and kinetics experiments reveal a consecutive redox pathway, with *CO being a key surface intermediate that either desorbs or is further hydrogenated to CH4. We propose that the selectivity change is due to the transient coverages of *CO and *H over the Ni surface during temperature pulsing, which facilitates CO desorption and suppresses the subsequent deep deoxygenation and hydrogenation to CH4.