The dual electronic effects of alloying and synergistic surface oxygen vacancy in PtCo/CeZrOx enhance NOx reduction by CO
image: In the low-temperature zone (100-200 ℃, phase I), The dominant NO decomposition and minor CO-SCR pathways originate from the interaction between NO adsorbed on negatively charged Pt sites and CO adsorbed on Co sites. As the temperature gradually increases (200-400 ℃, phase Ⅱ), the oxygen species captured by the electron-deficient SSOVs and the surface lattice oxygen become activated to promote the adsorption and transformation of NO and CO (①). Concurrently, ROS can also directly oxidize gaseous CO (②).
Credit: Nano Research, Tsinghua University Press
Controlling nitrogen oxide (NOx) emissions is a critical challenge for environmental protection and public health. The CO selective catalytic reduction of NO (CO-SCR) technology stands out for its unique ability to simultaneously eliminate both NO and CO pollutants. Research has shown that alloy catalysts exhibit superior electronic modulation capabilities, while cerium zirconium oxide solid solution (CeZrOx) enhance N2 selectivity through synergistic surface oxygen vacancies (SSOVs). However, existing catalysts struggle to maintain both high selectivity and stability under oxygen-rich conditions, severely limiting their practical application.
Addressing this challenge, a research team led by Prof. Yongjun Ji from Beijing Technology and Business University has made a significant breakthrough. They developed a multifunctional composite catalyst featuring a low-content PtCo alloy (0.01% Pt, 0.04% Co) supported on a CeZrOx solid solution rich in SSOVs. By leveraging the dual electronic effects of alloying and SSOVs, this catalyst achieves both high selectivity and stability under oxygen-rich conditions (5% O2), significantly improving CO-SCR performance and offering an innovative solution for industrial exhaust purification.
The findings were published on November 17, 2025, in Nano Research.
"In this study, we optimized the electronic structure of the catalyst by precisely tuning the synergy between alloying and oxygen vacancies," explained Prof. Ji, corresponding author of the study and a professor at the School of Light Industry Science and Engineering, Beijing Technology and Business University. "Under 5% O2, the catalyst achieves over 85% NO conversion at 300 ℃ while maintaining nearly 100% N2 selectivity during a 20-hour stability test—far surpassing conventional single-metal catalysts." Prof. Ji, recognized as a distinguished young talent in Beijing, specializes in environmental catalytic materials.
The exceptional performance of the PtCo/CeZrOx catalyst stems from its unique electronic modulation mechanism. The team discovered that the synergy between alloying effect and SSOVs effect facilitates electron transfer from SSOVs to the PtCo alloy, creating negatively charged Pt species (Ptδ−) and electron-deficient SSOVs. This dual electronic effect delivers multiple advantages: Negatively charged Pt enhances NO adsorption and dissociation; Electron-deficient SSOVs suppress O2 chemisorption while promoting reactive oxygen species generation; CO preferentially adsorbs on Co sites, minimizing competitive adsorption with NO.
"This dual effect not only optimizes reactant adsorption and activation but also significantly improves oxygen resistance and stability," Prof. Ji emphasized. Advanced characterization techniques, including XRD, HRTEM, and XPS, confirmed the coexistence of PtCo alloys and SSOVs and their electronic interactions.
In performance evaluations, the PtCo/CeZrOx catalyst demonstrated exceptional NO conversion efficiency, achieving nearly 100% at 400 ℃ while maintaining stable performance throughout extended 20-hour testing. Comparative analysis reveals this catalyst outperforms existing Pt-based, Co-based, and alloy catalysts in both activity and stability under oxygen-rich conditions.
The study provides a new design strategy for high-efficiency CO-SCR catalysts. The team plans to further refine the catalyst composition and advance its application in industrial waste gas treatment.
Other contributors include Huanli Wang, Dianxing Lian, Zhijin Zhang, Mohaoyang Chen, Guiyao Dai, Shujun Hou, Botao Liu, Ke Wu, Weiwei Zhang, from the School of Light Industry Science and Engineering, Beijing Technology and Business University, Beijing 100048, China; and Guofeng Zhao from the Anhui Basic Discipline Research Center for Clean Energy and Catalysis, College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241002, China.
This work was supported by by the National Natural Science Foundation of China (No. 22301012 and No. 21978299), the Research Foundation for Youth Scholars of Beijing Technology and Business University (No. QNJJ2022-23), the R&D Program of Beijing Municipal Education Commission (No. KM202310011005), the Research Foundation for Advanced Talents of Beijing Technology and Business University (No. 19008020159), and the Shccig-Qinling Program (No. SMYJY202400134C).
About Nano Research
Nano Research is a peer-reviewed, open access, international and interdisciplinary research journal, sponsored by Tsinghua University and the Chinese Chemical Society, published by Tsinghua University Press on the platform SciOpen. It publishes original high-quality research and significant review articles on all aspects of nanoscience and nanotechnology, ranging from basic aspects of the science of nanoscale materials to practical applications of such materials. After 18 years of development, it has become one of the most influential academic journals in the nano field. Nano Research has published more than 1,000 papers every year from 2022, with its cumulative count surpassing 7,000 articles. In 2024 InCites Journal Citation Reports, its 2024 IF is 9.0 (8.7, 5 years), and it continues to be the Q1 area among the four subject classifications. Nano Research Award, established by Nano Research together with TUP and Springer Nature in 2013, and Nano Research Young Innovators (NR45) Awards, established by Nano Research in 2018, have become international academic awards with global influence.