Porous hollow Ni/CaO dual functional materials for integrated CO2 capture and methanation

Excessive CO2 2 emissions present significant environmental and energy challenges, driving the need for effective strategies to reduce CO2. 2 . Integrated CO2 2 capture and utilization (ICCU) processes have drawn considerable attention by combing carbon capture and catalytic conversion in a unified process. The rational design of efficient dual-functional materials (DFMs) is key to achieving high-efficiency ICCU processes. Here, we synthesized a series of CaO-based DFMs with varying Ni loadings, in which the porous hollow CaO prepared by a sacrificial template method was employed as the adsorbent. The porous hollow structure are effectively to improve the diffusion of CO2 2 species and provide sufficient space for volume expansion after CO2 2 capture. The optimized conditions for adsorption and catalytic sites were determined to be at 550 degrees C with 5wt% Ni loading. Under these conditions, the adsorption capacity of 5 %Ni/CaO-P reached 7.02 mmol g - 1 DFM, , with a CH4 4 yield of 2.85 mmol g - 1 DFM and a CH4 4 selectivity of 94.09 %. After 19 cycles, the adsorption capacity of 5 %Ni/CaO-P is maintained at 4.50 mmol g - 1 DFM with a CH4 4 yield remaining stable at 0.50 mmolg- g - 1 DFM due to the slight sintering of Ni species. Integrated CO2 2 capture and methanation offer a pathway for carbon recycling, emissions reduction, and sustainable development.