Tuning oxygen activity via Ni doping in LaFeO3 for staged chemical looping gasification of plastic waste

Zhao, Tingman, Wu, Shijie, Lu, Chunqiang, Yao, Dingding and Tu, Xin ORCID: 0000-0002-6376-0897 (2026) Tuning oxygen activity via Ni doping in LaFeO3 for staged chemical looping gasification of plastic waste. Applied Catalysis B: Environment and Energy, 383. p. 126085. ISSN 0926-3373

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Abstract

A novel staged chemical looping gasification (SCLG) process is developed for sustainable production of hydrogen-rich syngas from plastic waste, where precise modulation of oxygen activity in oxygen carriers (OCs) is crucial. Herein, a series of LaFe<inf>1-x</inf>Ni<inf>x</inf>O<inf>3</inf> (x = 0–0.8) perovskite-type OCs were synthesized and systematically evaluated in the SCLG of polypropylene. The Ni-doped perovskites demonstrated significantly enhanced syngas production compared with undoped LaFeO<inf>3</inf>, with LaFe<inf>0.6</inf>Ni<inf>0.4</inf>O<inf>3</inf> exhibiting the optimum performance. This catalyst achieved a syngas yield of 168.4 mmol/g<inf>plastic</inf>, together with a CO selectivity of 92.4 % and carbon conversion of 91.5 %. Notably, it maintained these activities over multiple redox cycles without significant degradation. The optimized oxygen activity achieved through Ni doping originates from the significantly increased concentration of oxygen vacancies, which facilitates the transformation of Fe²⁺ to higher valence states (Fe³⁺/Fe⁴⁺). This accelerates oxygen migration and promotes the release of lattice oxygen, resulting in greater CO generation during the fuel stage. In addition, Ni doping enhances the oxygen recovery capability of reduced OCs through improved steam adsorption and subsequent dissociation, as further supported by density functional theory (DFT) calculations. This study provides new insights into oxygen activity modulation, advancing the understanding of chemical looping gasification and informing catalyst design strategies for sustainable H<inf>2</inf>-rich syngas production from plastic waste.

Item Type:	Article
Uncontrolled Keywords:	34 Chemical Sciences, 3406 Physical Chemistry, 7 Affordable and Clean Energy, 12 Responsible Consumption and Production
Divisions:	Faculty of Science & Engineering Faculty of Science & Engineering > School of Engineering Faculty of Science & Engineering > School of Engineering > Electrical Engineering and Electronics
Depositing User:	Symplectic Admin
Date Deposited:	22 Oct 2025 10:36
Last Modified:	28 Oct 2025 04:22
DOI:	10.1016/j.apcatb.2025.126085
Related Websites:	Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3194950