Crystal-in-Amorphous Vanadate Catalysts for Universal Poison-Resistant Elimination of Nitric Oxide

The deactivation of catalysts by metal poisons is a pressing and ongoing concern in heterogeneous catalysis. The design of catalysts with good resistance to metal poisons under harsh reaction conditions is a formidable challenge. Herein, we report on the delicate engineering of a catalyst comprising alpha-Fe2O3 crystals embedded in amorphous FeVO4, which exhibits remarkable resistance to metal poisons during the catalytic elimination of nitric oxide. X-ray atomic pair distribution function analysis, confocal and in situ Raman spectra, and vertex component analysis were used to show that amorphous FeVO4 provides the ion channel, enabling the migration of poisons away from the surface-active sites and into an inner sacrifice zone. Crystal-in-amorphous catalysts are universally resistant to metal poisons due to the migration of these poisons caused by differences in chemical potential and low diffusion energy barriers. The embedded alpha-Fe2O3 crystals act as a stabilizing skeleton for the amorphous FeVO4, conferring good robustness to the catalyst, even after an aging process. Our work represents a rational design of crystal-in-amorphous structure catalysts, providing an alternative approach to fabricating excellent poison-resistant catalysts for other heterogeneous catalysis processes.

Automated summary

In this study, a catalyst comprising alpha-Fe2O3 crystals embedded in amorphous FeVO4 was engineered to exhibit remarkable resistance to metal poisons during the catalytic elimination of nitric oxide. The amorphous FeVO4 provided an ion channel for the migration of poisons away from the surface-active sites, while the crystal-in-amorphous structure enabled the catalyst to be universally resistant to metal poisons. The embedded alpha-Fe2O3 crystals acted as a stabilizing skeleton for the amorphous FeVO4, ensuring good robustness of the catalyst even after aging.