Pavan Adriano F, Ling Chris D
University of Sydney, School of Chemistry, Sydney, NSW 2006, Australia.
Inorg Chem. 2022 May 2;61(17):6555-6561. doi: 10.1021/acs.inorgchem.2c00384. Epub 2022 Apr 20.
We positively identified and quantified the solid-state phases involved in the carbonation/decarbonation cycle of NaZrO when used for carbon capture. Previous work had only qualitatively inferred the phases present using diffraction pattern matching and thermogravimetric analysis. Here, we used the Rietveld-refinement method to analyze synchrotron X-ray and neutron powder diffraction data from samples treated . We then confirmed and extended our findings by diffraction using a purpose-built gas-flow apparatus. This allowed us to resolve discrepancies in the earlier literature concerning which phases are present during the carbonation and regeneration processes. A key finding is the simultaneous presence of the monoclinic and tetragonal phases of ZrO and that the "metastable" tetragonal phase is favored by smaller particles and can reincorporate into the bulk but the stable monoclinic phase does not. The result will help optimize the cycling of NaZrO.
当用于碳捕获时,我们对参与NaZrO碳酸化/脱碳酸化循环的固态相进行了明确鉴定和定量分析。先前的工作仅通过衍射图谱匹配和热重分析定性推断了存在的相。在此,我们使用Rietveld精修方法分析了处理过的样品的同步加速器X射线和中子粉末衍射数据。然后,我们使用专门构建的气流装置通过衍射确认并扩展了我们的发现。这使我们能够解决早期文献中关于碳酸化和再生过程中存在哪些相的差异。一个关键发现是ZrO的单斜相和四方相同时存在,并且“亚稳”四方相更有利于较小的颗粒,并且可以重新并入主体中,但稳定的单斜相则不能。该结果将有助于优化NaZrO的循环。