Facile synthesis and efficient nickel-based photothermal catalyst for selective production of CH4 and CO

Title : Facile synthesis and efficient nickel-based photothermal catalyst for selective production of CH4 and CO

Abstract:

CO₂ hydrogenation is not only a significant technical route for carbon emission reduction, but also contributes to the production of various value-added chemicals. Nickel (Ni) has been extensively employed in catalytic conversion of CO₂ due to its wide accessibility, lower cost and good activity. Herein, the catalysts for CO₂ hydrogenation were prepared by loading Ni on mesoporous silica with highly ordered mesoporous structure, which effectively improves the dispersion of metal particle and prevents the sintering at high temperatures. Besides, the addition of La₂O₃ as promoter in the Ni-based catalyst gives rise to the number of medium basic sites and mitigates the recombination of photogenerated electron-hole pairs, which reinforces the catalytic performance in CO₂ hydrogenation. In this study, the introduction of light irradiation at 500 ? lead to the transferring of electrons from SiO₂ to Ni²⁺ and La³⁺, which is different from that at room temperature with the electrons flow from La³⁺ to Ni²⁺. Moreover, the catalyst exhibits the highest Ni⁰/Ni²⁺ ratio under photothermal conditions, which results in the considerable CO₂ conversion of 70% and CO selectivity of 97%. The satisfying dispersion effect of mesoporous silica and the stable photo-electric conversion ability of La₂O₃ modified Ni-based catalyst bring about the fulfilling stability in long-term photothermal catalytic reactions. More importantly, CH₄ or CO could be selectively obtained with high selectivity (>95%) by adjusting the photothermal catalytic conditions via simple operation. It is envisage that the catalyst and technical method in this study holds great potential in practical industrial production.

Biography:

Guoshu Deng received her master degree from University of Glasgow in 2021, and she is currently a Ph.D. candidate at Southeast University. Her research focuses on integrated CO₂ capture and conversion with dual-function materials, with the aim of simultaneously capture CO₂ from simulated flue gas (low CO₂ concentration) and convert it into value-added chemicals such as methane, which saves great energies and expenses in the process of incurred in CO₂ compression and transportation processes of conventional carbon capture, utilization, and storage (CCUS) technology.