The dual electronic effects of alloying and synergistic surface oxygen vacancy in PtCo/CeZrO_x enhance NO_x reduction by CO

The regulation of electron transfer is crucial for enhancing the catalytic efficiency of catalysts. Currently, CO selective reduction of NO_x (CO-SCR) catalysts with surface synergistic oxygen vacancies (SSOVs) or alloyed components exhibit superior performance but face challenges of reduced activity and stability in oxygen-rich environments. Here, we demonstrate a strategy that combines PtCo alloys (0.01% Pt; 0.04% Co) with SSOVs in cerium zirconium oxide solid solution to interactively modulate the electronic structure, resulting in a significant enhancement of both the activity and stability of the catalyst under oxygen-rich conditions. This catalyst achieved over 85% NO conversion at 300 °C and 5% O₂, while maintaining approximately 100% N₂ selectivity during 20 h-stability testing, surpassing the performance of the monometallic catalysts. This enhancement arises from the synergistic electronic effects of alloying and SSOVs, which generate negatively charged Pt that facilitates NO adsorption and dissociation, while concurrently producing electron-deficient SSOVs that weaken O₂ chemisorption and promote the formation of moderate reactive oxygen species. Moreover, the preferential adsorption of CO on Co sites alleviates competitive adsorption.