Insights into the cyclic CO2 capture and catalytic methanation over highly performing Li-Ru/Al2O3 dual function materials
Insights into the cyclic CO2 capture and catalytic methanation over highly performing Li-Ru/Al2O3 dual function materials
复制标题
DOI：
10.1016/j.cej.2021.131275
复制
发表时间：
2021-07-28
影响因子：
15.1
通讯作者：
Lisi, Luciana
中科院分区：
文献类型：
--
作者：
Cimino, Stefano;Russo, Roberta;Lisi, Luciana
在双功能吸附剂-催化剂材料上使用可再生氢气的组合CO2捕集和原位甲烷化是一种化学循环过程，具有提高效率和降低当前CCU技术成本的强大潜力。在这项工作中，我们着手开发高性能的锂-钌/Al 2 O3，研究交替的CO2吸附和氢化阶段所涉及的协同和机理方面。具有低Ru负载的催化剂（最大1%wt.）和固定的分散在Al 2 O3球促进与不同量的Li（1- 5%wt.）采用BET、PSD、XRD、H-2化学吸附、CO2-TPD、TGMS、H-2 -TPSRx和CO2连续流动催化甲烷化等手段对催化剂进行了表征。在固定床反应器中研究了瞬态CO2储存/甲烷化循环，该反应器在几个温度水平（250-350 ℃）下操作，具有可变持续时间的交替进料条件。还通过原位DRIFT比较xLi-Ru/Al 2 O3材料与参考Ru/Al 2 O3催化剂的结果来研究循环CO2吸附和甲烷化。锂铝酸盐吸附剂相和催化钌位点之间在纳米尺度上存在的有利协同作用增强了DFM的固有活性，可以在低贵金属负载的情况下保证高的甲烷生产率和选择性。
The combined CO2 capture and in-situ methanation using renewable hydrogen over dual function sorbent-catalyst materials is a chemical looping process with strong potential to increase the efficiency and reduce the cost of current CCU technologies. In this work, we set out to develop highly performing Lithium-Ruthenium/Al2O3 investigating synergic and mechanistic aspects involved in the alternate CO2 adsorption and hydrogenation phases. Catalysts with low Ru loading (max 1% wt.) and fixed dispersion on Al2O3 spheres were promoted with variable amounts of Li (1-5% wt.) and characterized by BET, PSD, XRD, H-2 chemisorption, CO2-TPD, TGMS, H-2 -TPSRx and CO2 catalytic methanation under continuous flow conditions. Transient CO2 storage/ methanation cycles were studied in a fixed bed reactor that was operated at several temperature levels (250-350 degrees C) with alternate feed conditions of variable duration. The cycled CO2 adsorption and methanation were also investigated by in-situ DRIFT comparing results for xLi-Ru/Al2O3 materials against the reference Ru/Al2O3 catalyst. The favourable synergism existing at the nanoscale between the Li-aluminate sorbent phase and the catalytic Ru sites enhances the intrinsic activity of the DFMs that can guarantee high methane productivity and selectivity with low noble metal loadings.