Syngas and pure hydrogen are essential feedstocks for industrial processes ranging from oil refining to fuel cells, yet conventional steam methane reforming operates at approximately 900°C with high energy consumption and greenhouse gas emissions. Chemical looping partial oxidation of methane and water splitting (CL POM-WS) offers a promising alternative, but existing oxygen carriers (OCs) typically require temperatures above 700°C. Now, researchers from Tohoku University, led by Professor Chunli Han, Dr. Akira Yoko, and Professor Tadafumi Adschiri, have developed a breakthrough NiO/cCeO 2 oxygen carrier that enables efficient low-temperature operation at ≤600°C.
Why This Oxygen Carrier Matters
Traditional Ni-based OCs suffer from a critical trade-off: high activity for CH 4 dissociation leads to severe coke deposition and rapid deactivation. The novel NiO/cCeO 2 OC overcomes this limitation through precise microstructural control—balancing CH 4 activation with lattice oxygen supply to suppress CH 4 cracking while maintaining high syngas selectivity.
Innovative Design and Mechanism
The material is synthesized using cubic CeO 2 nanoparticles as support with surface-fused NiO through controlled loading and reaction-driven activation pretreatment. This activation induces Ni migration from uniform dispersion to surface-enriched 10–20 nm Ni/NiO nanoparticles, accompanied by a spin-state transition from low-spin to high-spin Ni 2+ . The cubic CeO 2 support exerts a confinement effect that restricts Ni agglomeration, while its well-matched lattice oxygen supply capacity ensures selective partial oxidation rather than complete oxidation or cracking.
Outstanding Performance
The optimized 2.5NiO/cCeO 2 OC achieves >98.5% CO selectivity with H₂/CO ≈ 2 in the POM step, and produces nearly pure H₂ (>99%) in the WS step at 600°C—200–300°C lower than conventional systems. The material demonstrates exceptional stability with 99.98% capacity retention over 40 cycles (approximately 20 hours) without coke deposition. The oxygen recovery rate exceeds 75%, and the system maintains performance across a broad 500–800°C operating window.
Applications and Future Outlook
This low-temperature OC makes CL POM-WS highly competitive with steam methane reforming in terms of energy efficiency, process safety, and gas purification costs. The elimination of air separation units and reduced downstream separation requirements significantly enhance process economics. This work establishes precise active-site control strategies for developing next-generation oxygen carriers, advancing sustainable hydrogen and syngas production for industrial decarbonization.
Nano-Micro Letters
News article
Low‑Temperature CH4 Reforming and Water Splitting with Activated NiO/CeO2 as Oxygen Carrier
17-Mar-2026