Robust ceramic hollow fiber membrane reactor for dual syngas in-tandem production by coupling of CO2-H2O co-decomposition with CH4 partial oxidation

• Coupled CO 2 -H 2 O co-decomposition with POM on SDC-LCAF membrane reactor. • Co-production of H 2 /CO syngas at both sides of the membrane. • Syngas production rates of 10.79 (shell) and 18.46 (lumen) mL min −1 cm −2 . • Coupled CO 2 -H 2 O co-decomposition with POM for more than 100 h. Membrane reactor technology utilizing O 2 -selective mixed-ionic electronic conducting materials enables the production of syngas through thermochemical conversion of CO 2 and H 2 O into CO and H 2 at a relatively low temperature below 1000 °C. This syngas production can be further intensified by coupling with partial oxidation of methane (CH 4 ) (POM), which increases the overall syngas production rate. Additionally, the high O 2 permeability of the membrane reactor enables a tunable H 2 /CO ratio in syngas production through feed gas flow control and reduced localized hotspots to minimize carbon buildup, thereby enhancing the overall process efficiency and stability. Herein, we presented a promising hollow fiber membrane material composed of 60 wt% Sm 0.2 Ce 0.8 O 2−δ -40 wt% La 0.8 Ca 0.2 Al 0.3 Fe 0.7 O 3-δ (SDC-LCAF) loaded with 10 wt% Ni/SDC for CO 2 -H 2 O co-decomposition (shell side) and coated with Ni/LaNiO 3 /γ-Al 2 O 3 for POM (lumen side), which exhibited no performance degradation over 100 h of continuous operation at 950 °C. The CO 2 -H 2 O co-decomposition has achieved a syngas production rate of 10.79 mL min −1 cm −2 , with a H 2 :CO ratio of ∼ 2 and a CO 2 conversion of 47.43 %. Besides, the syngas production rate by POM was recorded at 18.46 mL min −1 cm −2 and a maximum H 2 :CO ratio of ∼ 1.8 was observed on the lumen side, whereas the CH 4 conversion and CO selectivity have reached 96.17 % and 93.1 %, respectively. Further investigation into the effects of gas compositions and flow rates to the membrane reactor performances as well as the underlying reaction mechanisms were systematically discussed. The membrane reactor’s ability in efficient syngas production showcases its potential to facilitate sustainable methanol and hydrogen synthesis through efficient conversion of greenhouse gases and hydrocarbon utilization, thereby advancing the sustainable carbon value chain.