Highly efficient and durable syngas production over one-step synthesized synergistic oxygen carriers in biomass chemical looping gasification

•Successful one-step synthesis of NiO-LaFeO3 synergistic OCs.•The ex-situ configuration is more conducive to hydrocarbon conversion to syngas.•The mutual mode is more suitable for increasing and modulating the H2/CO ratio.•The 0.5NLF OCs showed excellent stability and syngas selectivity over 50 cycles.•A technical route for efficient and durable syngas production was explored.