Engineering Run+–OV–Ce3+ interfaces in Ru/CeO2 via air calcination and CO activation for enhanced water–gas shift catalysis

The catalytic efficiency of Ru/CeO 2 in the water–gas shift (WGS) reaction is frequently limited by its insufficient capacity to activate water molecules, which substantially impairs low-temperature performance. In this study, an interfacial engineering strategy combining air calcination with CO reduction is developed to construct a Ru/CeO 2 -R catalyst enriched with Ru n+ –O V –Ce 3+ interfacial structures. This specially designed interface significantly enhances the activity of low-temperature WGS. Advanced characterization techniques, including XPS, TEM, Raman spectroscopy, and in situ DRIFTS, demonstrate that Ru n + species reduce excessive CO adsorption, thereby enhancing reaction selectivity. Meanwhile, oxygen vacancies facilitate water dissociation and increase the reaction rate. Consequently, the Ru/CeO 2 -R catalyst achieves an impressive CO conversion rate of 9.56 mol CO ·g Ru −1 h −1 at 200 °C. This research introduces a straightforward and controllable method for tailoring interfacial electronic structures, offering valuable insights for the rational design of highly efficient catalysts for low-temperature WGS.