Self-sustained CO Combustion Induced by CuCe_0.75Zr_0.25O_y Catalysts with Different Pore-forming Methods

ABSTRACT

CO self-sustaining combustion, induced by a CuCe_0.75Zr_0.25O_y catalyst, has been confirmed experimentally as an effective strategy to reduce serious environmental pollution and energy waste, which is caused by direct combustion of conventional converter gas in the steelmaking industry. In this paper, the effects of CuCe_0.75Zr_0.25O_y catalysts prepared by a sol-gel method via three different pore-forming agents (oxalic acid, cellulose and thermal decomposition) were investigated for their catalytic activity of self-sustained CO combustion. Additionally, characterization methods were used to obtain the structural properties of each catalyst. The results obtained show that the CuCe_0.75Zr_0.25O_y catalyst, as a sol-gel pore-forming agent, prepared from cellulose exhibits the highest activity among the three catalysts. Under the condition of a reaction gas (3% CO+5% O₂/N₂), the T₁₀ (70°C), T₅₀ (73°C) and T₉₀ (78°C) of the cellulose catalyst are obviously lower than those of the other catalysts, where T₁₀, T₅₀ and T₉₀ denote the reaction temperature corresponding to the CO conversion of 10%, 50% and 90%, respectively. The reason is that the cellulose pore-forming agent promotes the formation of a multistage porous structure, which strengthens the synergistic effect between the Cu and Ce catalysts and changes the redox property of the overall catalyst. On the one hand, the strong synergy between CuO and CeO₂ adjusts the dispersion and chemical state of copper nanoparticles. On the other hand, the oxygen vacancies generated locate at the copper-cerium interface enhance the ability of oxygen storage and oxygen release of the catalyst.

KEYWORDS:

• CuCe_0.75Zr_0.25O_y catalyst
• carbon monoxide
• self-sustained combustion
• pore-forming way

Acknowledgments

This work is financially supported by the National Natural Science Foundation of China (51776216, 51736010). The work is also supported by Dalian National Laboratory for Clean Energy, Dalian 116023, China and the Transformational Technologies for Clean Energy and Demonstration, Strategic Priority Research Program of the Chinese Academy of Sciences, Grant No.XDA21040500.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [51736010,51776216] and the Transformational Technologies for  Clean Energy and Demonstration, Strategic Priority Research Program of the Chinese Academy of Sciences,Grant No.XDA21040500.