Performance study of nickel-potassium/calcium oxide catalyst for carbon dioxide capture and conversion

In the context of the urgent need to reduce global greenhouse gas emissions, the utilization of CO₂ as a resource has emerged as a key strategy for addressing both climate change and the energy crisis. Carbon dioxide capture and conversion technology is considered one of the effective measures to tackle this challenge. This study prepared CaO-based catalysts loaded with active metals Ni and K to enhance CO₂ capture and improve reverse water-gas shift (RWGS) performance. By tuning reaction temperature and Ni loading, the effects of different operating conditions on CO production during CO₂ hydrogenation were systematically investigated. The results show that at 15% Ni loading, the catalyst achieved a CO₂ adsorption capacity of 16.88mmolg−1 at 600 °C, while delivering a CO yield of 8.53mmolg−1 with 97% selectivity. The catalyst may be related to a relatively stable Ni(0)/NiO redox equilibrium, which may be related to the synergistic effects of oxygen vacancies and potassium promotion. In addition, the optimized pore structure further promoted CO production, ultimately enabling the highest observed CO yield. After ten reaction cycles, the target CO yield of the 15Ni1K/CaO catalyst showed only a slight decrease, from 8.53mmolg−1 to 7.32mmolg−1, demonstrating moderate cyclic stability.