Construction Inverse NiCoCeAl-LDO/Ni Catalyst for Effective CO 2 Methanation at Low Temperature

Abstract

Developing cost-effective CO 2 methanation catalysts that perform efficiently at low temperatures remains a significant challenge in enabling carbon-neutral energy cycles. Traditional catalysts often suffer from rapid deactivation due to unavoidable metal sintering and carbon deposition. Herein, this paper constructed a novel inverse NiCoCeAl-LDO/Ni catalyst by in situ growth of Layer Dioxide (LDO) on Ni substrate, which can effectively overcome these issues. The inverse configuration not only physically confines active Ni species but also creates rich oxide-metal interfaces that promote strong electronic oxide-metal interactions (EOMI).Systematic characterization reveals that Co doping facilitates the reduction of Ni²⁺ to metallic Ni⁰, thereby increasing hydrogen dissociation sites and enhancing hydrogen spillover. Concurrently, the Ce³⁺/Ce⁴⁺ redox pairs generate abundant oxygen vacancies, which lower the activation barrier for both catalyst reduction and CO₂ hydrogenation. As a result, the optimized 3LDO/0.6Ni catalyst achieves exceptional low-temperature performance, with 97.4% CO₂ conversion and almost 100% CH₄ selectivity at 260 °C under 2 MPa. In situ DRIFTS studies identify the formate pathway as the dominant reaction mechanism. Remarkably, the catalyst exhibits outstanding stability over 100 h on stream with no detectable decline in activity or selectivity. This work provides a fundamental understanding of interface engineering in inverse catalysts and offers a viable strategy for designing highly active, stable, and low-temperature CO₂ methanation systems.