Directional induction of hydrogen spillover enhancing H2O resistance of Ca-Ni-based dual-function materials for integrated CO2 capture and in-situ methanation

Integrated carbon capture and utilization (ICCU) technology based on Ca-Ni-based dual-function materials (DFMs) is an important carbon reduction measure. However, the severe performance degradation of DFMs caused by H 2 O is a challenge for ICCU. This study aims to improve the H 2 O resistance of Ce-doped Ni-Ca-based DFMs by Mg-Y co-doping. After 10 cycles with H 2 O, the carbon capture capacity, methane yield, and methane production rate were maintained at 11 mmol/g, 10.5 mmol/g, and 121.18 μmol/g·min, respectively. Changing the water vapor content (0 ∼ 10 %) has little effect on its performance. Characterizations (XRD, TEM, XPS, H 2 -TPR, CO 2 -TPD, NH 3 -TPD, H 2 -TPSR, and in-situ DRIFTS) and experiments (carbonation and conversion by H 2 O experiments) revealed a directional induced hydrogen spillover mechanism: The strong interactions of Ni-Mg and Ni-Y reduce the particle size and inhibit agglomeration; meanwhile, H 2 O can activate the Y-doped Ni-based catalyst in the carbonation process, inducing hydrogen spillover into the methanation reaction path during the subsequent conversion process, where Mg-promoted generated formaldehyde species act as a vital intermediate. It provides a novel idea to enhance the H 2 O resistance of DMFs to achieve stable ICCU performances.