CO<sub>2</sub> Hydrogenation to Methanol and Ethanol on In<sub>2</sub>O<sub>3</sub>-Based Single-Atom Catalysts and a New Scaling Relation
Deshuai Yang, Huili Lu, Guixiang Zeng, Zhao‐Xu Chen
Abstract
Conversion of CO 2 into high-value chemicals is a hot issue both industrially and scientifically, and the development of suitable catalysts is the key problem. Using density functional theory (DFT) calculations and microkinetic simulations, we investigated the mechanisms for reduction of CO 2 to methanol and ethanol on the iridium-doped In 2 O 3 single-atom catalyst, which exhibits high selectivity to ethanol. The favorable pathways and two key steps controlling the formation and selectivity of methanol and ethanol were identified. Further calculations of the energy barriers for the two key steps on the other nine single-metal-atom-doped In 2 O 3 show that Mn-doped In 2 O 3 may possess higher selectivity to ethanol than Ir-doped In 2 O 3, while Ru-, Fe-, and Rh-doped In 2 O 3 might be good catalysts for methanol. Furthermore, we found that there exists a linear relation (ADTS relation) between the CO 2 separate adsorption energies and the adsorption energies of transition states. It is demonstrated that for a bimolecular (A + B) surface reaction, the ADTS relation holds true when the sum of the interactions of B with A and B with the surface are constant. The present work also outlines a methodology to identify reaction descriptors to screen catalysts on the basis of reaction mechanisms and microkinetic analysis.