1. Study on the structural evolution and heat transfer performance of Cu supported on regular morphology CeO2 in CO catalytic combustion and chemical looping combustion.
- Author
-
Huang, Junqin, Liu, Huan, Zhang, Chenhang, Bin, Feng, Wei, Xiaolin, Kang, Running, and Wu, Shaohua
- Subjects
- *
CHEMICAL-looping combustion , *COPPER , *HEAT transfer , *ENERGY conversion , *CERIUM oxides , *AGGLOMERATION (Materials) , *ENERGY conservation - Abstract
Chemical looping combustion (CLC) and catalytic combustion (CC), which are potential technologies to promote CO→CO 2 efficient conversion and energy conservation for the steelmaking off-gas, are investigated in reaction activity, structure evolution catalysts/oxygen carriers (OCs) and energy recovery using Cu/CeO 2 materials. Activity results suggest that the rod-shaped samples with well-defined (100) crystal faces exhibit higher activity than the sphere-shaped samples with (111) crystal faces, obtaining the optimized copper content of 3 wt%. IR spectra confirmed the proposed reaction pathway that the CO adsorbed on copper sites (Cu+–CO) at the Cu–Ce interface reacts with adjacent surface lattice oxygen. The gaseous oxygen continuously migrates to the external surface of materials, thus resulting in strongly exothermic CO self-sustained combustion during CC. Such a violent reaction does not cause obvious evolution of chemical composition, crystalline phase and structure. Since the active lattice oxygen is gradually consumed but not replenished by external gaseous O 2 in time, CO combustion is not self-sustained during CLC. Therefore, the reduction cycle is no longer confined to the surface of the material but penetrates deep into its body, which accelerates Cu+ enrichment at the surface and leads to irreversible sintering and agglomeration of the material. • The activity of nanorod and nanosphere Cu/CeO 2 was compared. • CLC reaction is more exergy efficiency when burning. • The reason of catalyst deactivation in CLC was investigated. • The migration of active oxygen species in CC and CLC was compared. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF