Effects of Ni loading and Ce doping on a CaO-based dual function material for integrated carbon capture and in situ methanation

Abstract

Integrated CO₂ capture and utilization (ICCU) emerges as an effective strategy for reducing CO₂ emissions, offering benefits such as facility simplification and improved energy efficiency. To further optimize the performance of ICCU-methanation dual-function materials (DFMs), a Ni/CeNiCa DFM featuring a Ce promoter and Ni pre-doping was synthesized using a one-pot method and impregnation technique. This resulted in an impressive CO₂ capture capacity of 11 964 μmol g_DFM⁻¹ and a CH₄ production yield of 11 061 μmol g_DFM⁻¹. The pre-doping of Ni serves as a promoter and catalyst, whereas the impregnation-loaded Ni enhances the catalytic effectiveness of the DFM. Despite its impact on the reduction of NiO, the Ce doping proves valuable by modulating the active crystal surface of Ni, thus enhancing the methane production rate. In addition, 3% O₂ addition barely influences the CO₂ capture capacity and CH₄ production yield but slightly inhibits the CH₄ production rate. Furthermore, 500 ppm NO_x can have severe irreversible effects on the adsorbent, indicating that DeNO_x facilities are necessary for the application of the ICCU system.