Balancing surface acidity, oxygen vacancies and Cu+ of CuOx/CeO2 catalysts by Nb doping for enhancing CO oxidation and moisture resistance and lowering byproducts in plasma catalysis. (10th October 2021)

• Record Type: Journal Article
• Authors: Zhang, Jian; Wang, Lisha; Hu, Xueyu; Shao, Qi; Xu, Xiaoming; Long, Chao
• Is Part Of: Journal of cleaner production. Volume 318(2021)
• Publication Date: 2021-10-10
• Subjects: Cu/Ce-based catalysts -- Plasma catalysis -- Moisture resistance -- Ozone byproduct; Factory and trade waste -- Management -- Periodicals; Manufactures -- Environmental aspects -- Periodicals; Déchets industriels -- Gestion -- Périodiques; Usines -- Aspect de l'environnement -- Périodiques; 628.5
• DOI: 10.1016/j.jclepro.2021.128564
• Languages: English
• ISSNs: 0959-6526

Abstract

Abstract: The development of a non-noble metal catalyst is a challenging task in plasma catalysis to achieve high CO conversion and low amount of by-products (O3 and NOx ) under low energy input and high humidity conditions. In this study, we have prepared several Nb-doped CuOx /CeNbOx catalysts with various Ce/Nb molar ratios. Among them, CuOx /Ce0.9 Nb0.1 Ox catalyst exhibited the highest CO conversion (>90%) and the lowest by-product emissions (O3 < 5 ppm; NOx < 20 ppm) at low energy density (~600 J/L) in plasma catalytic CO oxidation. Furthermore, it remained good stability under moisture-rich conditions (5.2% H2 O). We employed XPS, UV-Raman, O2 -TPD, NH3 -TPD and in situ DRIFTS to elucidate the origin of enhancement effects. It was found that the appropriate amount of niobium doping well balanced the relationship among Cu +, oxygen vacancies and surface acidity, and inhibited the competitive adsorption of H2 O. The findings can provide an avenue to solve the problems of incomplete oxidation and by-product emissions in the application of plasma technology. Graphical abstract: Image 1 Highlights: High CO conversion and few byproducts (O3 and NOx ) were obtained in plasma-assisted CuOx /CeNbOx catalysis. CuOx /CeNbOx kept stable catalytic activity under moisture-rich conditions (5.2% H2 O). Nb doping increased oxygen vacancies and acid sites and weakened the strength of CO–Cu + bond. Nb doping inhibited H2 O adsorption on CuOx /CeNbOx in the plasma catalysis.