Solid catalysts based on surface frustrated Lewis pairs (FLPs) are emerging materials for the activation of a variety of molecules, such as H2, CO2 and N2. In the prior works, the FLP sites are already formed in the starting catalysts and the acid and basic sites remain separated during the catalytic cycle. In this work, a new type of reactive site based on transient frustrated Lewis pairs (TFLPs) is proposed to explain the catalytic properties of single-atom Ce-doped α-Fe2O3(0 0 1) surface for selective reduction of NOx by NH3. The TFLP sites are formed during the process of the activation of reactants (NH3 and NO), and will disappear due to the structural reconstruction at the end of the catalytic cycle. By combining the DFT calculations and experimental results, it is inferred that the TFLP sites account for the variation of the preferred reaction pathways on α-Fe2O3(0 0 1) surface.

This work was supported by the National Natural Science Foundation of China (22372093, 21976111,) and Shandong Provincial Natural Science Foundation (ZR2019MB052). RA acknowledges funding by the Spanish MCIN (PID2019-104739GB-100/AEI/10.13039/501100011033). Some of the TEM works have been conducted at the Laboratorio de Microscopias Avanzadas (LMA) at Universidad de Zaragoza.

Peer reviewed