Raman Spectroscopy and Theoretical Calculation on Structure of Na2CO3-K2CO3-NaVO3 Molten Salts

doi:10.12068/j.issn.1005-3026.2024.03.004

Abstract

Abstract:

In the molten Na₂CO₃‐K₂CO₃， NaVO₃ can catalyze the in‐situ electroreduction of CO₂ to prepare high value‐added carbon‐based products. Studying the molten salt structure of Na₂CO₃‐K₂CO₃‐NaVO₃ system contributes to understand the electrode process mechanism and optimize the reaction conditions.The ionic structure of Na₂CO₃‐K₂CO₃‐NaVO₃ molten salt system at 1 073 K was investigated by a combination of Raman spectroscopy and quantum chemistry calculation using Gaussian and Molclus programs. The results show that VO₄^3- generated by the reaction of CO₃^2- and VO₃^- exists in the melts， apart from the presence of CO $3 2 -$ ， but VO₃^- doesn’t exist. VO₄^3- belongs to C₁ point group symmetry， and the band located at 802 cm^-1 in the Raman spectrum is caused by the symmetrical stretching vibration of the V—O bond in VO₄^3-. As the mass fraction of NaVO₃ in the system increases from 5% to 15%， the relative content of VO₄^3- increases dramatically， while that of CO₃^2- decreases accordingly in the molten salts.

Key words: NaVO₃, Na₂CO₃‐K₂CO₃ molten salt, Raman spectroscopy, quantum chemistry calculation, VO₄^3-

CLC Number:

O 433.4

Yi-fan ZHANG, Xian-wei HU, Jiang-yu YU, Zhao-wen WANG. Raman Spectroscopy and Theoretical Calculation on Structure of Na₂CO₃-K₂CO₃-NaVO₃ Molten Salts[J]. Journal of Northeastern University(Natural Science), 2024, 45(3): 331-336.

Figures/Tables 8

Fig.1 Schematic diagram of Raman spectra experimental device

Fig.2 Raman spectra of the carbonate system

Fig.3 Raman spectra of the Na2CO3?K2CO3?NaVO3 molten system with different NaVO3 contents at 1 073 K

Fig.4 Experimental Raman spectrum of molten NaVO3 at 1 073 K and the theoretically calculated Raman spectrum of VO3-

Fig.5 Optimized geometries of vanadium containing ions at the B3LYP level of theory（a）—VO43-；（b）—V2O74-.

Fig.6 Experimental Raman spectrum of Na2CO3? K2CO3?NaVO3 with w（NaVO3）=5% molten system at 1 073 K and the theoretically calculated Raman spectra of VO43- and V2O74-

Fig.7 Raman spectra of Na2CO3?K2CO3?NaVO3 with w（NaVO3）=5% at different temperatures

Fig.8 Area ratio of the band between VO43- and CO32- versus NaVO3 content in Fig.3 and the corresponding fitting curve

References 27

1	Ren N， Wu Y T， Wang T，et al.Experimental study on optimized composition of mixed carbonate for phase change thermal storage in solar thermal power plant［J］.Journal of Thermal Analysis and Calorimetry，2011，104：1201-1208.
2	Luo J， Deng C， Tariq N H，et al.Corrosion behavior of SS316L in ternary Li₂CO₃‑Na₂CO₃‑K₂CO₃ eutectic mixture salt for concentrated solar power plants［J］.Solar Energy Materials and Solar Cells，2020，217：110679.
3	Yin H Y， Tang D Y， Zhu H，et al.Production of iron and oxygen in molten K₂CO₃‐Na₂CO₃ by electrochemically splitting Fe₂O₃ using a cost affordable inert anode［J］.Electrochemistry Communications，2011，13（12）：1521-1524.
4	肖巍，朱华，尹华意，等.熔盐电化学低碳冶金新技术研究［J］.电化学，2012，18（3）：193-200.
	Xiao Wei， Zhu Hua， Yin Hua‐yi，et al.Novel molten‐salt electrolysis processes towards low‐carbon metallurgy［J］.Journal of Electrochemistry，2012，18（3）：193-200.
5	Jin G， Iwaki H， Arai N，et al.Study on the gasification of wastepaper/carbon dioxide catalyzed by molten carbonate salts［J］.Energy，2005，30（7）：1192-1203.
6	Li B R， Tan H， Liu Y，et al.Experimental investigations on the thermal stability of Na₂CO₃‐K₂CO₃ eutectic salt/ceramic composites for high temperature energy storage［J］.Renewable Energy，2020，146：2556-2565.
7	邓博文，尹华意，汪的华.CO₂高效资源化利用的高温熔盐电化学技术研究［J］.电化学，2020，26（5）：628-638.
	Deng Bo‐wen， Yin Hua‐yi， Wang Di‐hua.Highly efficient CO₂ utilization via molten salt CO₂ capture and electrochemical transformation technology［J］.Journal of Electrochemistry，2020，26（5）：628-638.
8	Chen Y F， Wang M Y， Zhang J T，et al.Green and sustainable molten salt electrochemistry for the conversion of secondary carbon pollutants to advanced carbon materials［J］.Journal of Materials Chemistry A，2021，9（25）：14119-14146.
9	邓博文，宋宇桥，毛旭辉，等.高温熔盐中CO₂的捕集与电化学资源化转化［J］.武汉大学学报（理学版），2016，62（1）：1-8.
	Deng Bo‐wen， Song Yu‐qiao， Mao Xu‐hui，et al.Capture and electrochemical conversion of CO₂ in high‐temperature molten salts［J］.Journal of Wuhan University （Natural Science Edition），2016，62（1）：1-8.
10	李世杰，王明涌，宋维力，等.熔盐电化学石墨化研究进展及展望［J］.工程科学学报，2022，44（4）：546-560.
	Li Shi‐jie， Wang Ming‐yong， Song Wei‐li，et al.Electrochemical graphitization in the molten salts：progress and prospects［J］.Chinese Journal of Engineering，2022，44（4）：546-560.
11	王宝辉，洪美花，吴红军，等.熔盐电解还原二氧化碳制碳技术［J］.化工进展，2013，32（9）：2120-2125.
	Wang Bao‐hui， Hong Mei‐hua， Wu Hong‐jun，et al.Study on carbon generation from carbon dioxide by molten salt electrolysis［J］.Chemical Industry and Engineering Progress，2013，32（9）：2120-2125.
12	Wang P， Wang M Z， Lu J Q.Electrochemical conversion of CO₂ into value‐added carbon with desirable structures via molten carbonates electrolysis［J］.RSC Advances，2021，11（46）：28535-28541.
13	Chen Y F， Wang M Y， Lu S L，et al.Electrochemical graphitization conversion of CO₂ through soluble NaVO₃ homogeneous catalyst in carbonate molten salt［J］.Electrochimica Acta，2020，331：135461.
14	王晨阳，孙理鑫，牛永生，等.FLiNaK-ZrF₄体系的Raman光谱及量子化学计算研究［J］.光散射学报，2016，28（1）：51-55.
	Wang Chen‐yang， Sun Li‐xin， Niu Yong‐sheng，et al.Raman spectroscopic and quantum chemistry calculation study on FLiNaK‐ZrF₄ system［J］.The Journal of Light Scattering，2016，28（1）：51-55.
15	Liu X Y， Wang B Z， Fu H Y，et al.Raman spectroscopic and theoretical studies on the structure of Ta （V） fluoro and oxofluoro complexes in molten FLiNaK［J］.Journal of Molecular Liquids，2021，337：116409.
16	刘晓伟，尤静林，王媛媛，等.Na₃AlF₆-Al₂O₃系熔盐结构的计算模拟与高温拉曼光谱［J］.中国有色金属学报，2014，24（1）：286-292.
	Liu Xiao‐wei， You Jing‐lin， Wang Yuan‐yuan，et al.Calculation simulation and high temperature Raman spectroscopic on structure of Na₃AlF₆‐Al₂O₃ molten salt system［J］.The Chinese Journal of Nonferrous Metals，2014，24（1）：286-292.
17	侯怀宇，尤静林，吴永全，等.碱金属碳酸盐的拉曼光谱研究［J］.光散射学报，2001，13（3）：162-166.
	Hou Huai‐yu， You Jing‐lin， Wu Yong‐quan，et al.Raman spectroscopic study of alkali carbonates［J］.The Journal of Light Scattering，2001，13（3）：162-166.
18	Carper W R， Wahlbeck P G， Griffiths T R.DFT models of molecular species in carbonate molten salts［J］.The Journal of Physical Chemistry B，2012，116（18）：5559-5567.
19	Lu T.Molclus program，version1.9.9.7［EB/OL］.（2021-11-23）［2022-03-16］..
20	Clark T， Chandrasekhar J， Spitznagel G W，et al.Efficient diffuse function‐augmented basis sets for anion calculations.III：the 3-21+G basis set for first‐row elements，Li‑F［J］.Journal of Computational Chemistry，1983，4（3）：294-301.
21	Lei X L， Haines K， Huang K，et al.DFT study of oxygen dissociation in molten carbonate［J］.The Journal of Physical Chemistry A，2015，119（33）：8806-8812.
22	Dolg M， Wedig U， Stoll H，et al.Energy‐adjusted ab initio pseudopotentials for the first row transition elements［J］.The Journal of Chemical Physics，1987，86（2）：866-872.
23	Lu T， Chen F W.Multiwfn：a multifunctional wavefunction analyzer［J］.Journal of Computational Chemistry，2012，33（5）：580-592.
24	Windisch C F， Cox J L， Greenwell E N.A Raman spectroscopic study of the interaction of cesium ions with oxyanions in carbonate melts［J］.Spectrochimica Acta Part A：Molecular and Biomolecular Spectroscopy，1997，53（12）：1981-1993.
25	Okazaki S， Matsumoto M， Okada I.Study of rotational and vibrational relaxation of the CO 3 2 - ion in molten alkali carbonates by Raman spectroscopy［J］.Molecular Physics，1993，79（3）：611-621.
26	Heimer N E， Del Sesto R E， Meng Z Z，et al.Vibrational spectra of imidazolium tetrafluoroborate ionic liquids［J］.Journal of Molecular Liquids，2006，124（1/2/3）：84-95.
27	Wang C Y， Chen X T， Wei R，et al.Raman spectroscopic and theoretical study of scandium fluoride and oxyfluoride anions in molten FLiNaK［J］.The Journal of Physical Chemistry B，2020，124（30）：6671-6678.

Raman Spectroscopy and Theoretical Calculation on Structure of Na₂CO₃-K₂CO₃-NaVO₃ Molten Salts

RichHTML

PDF (PC)

Knowledge

Abstract

Cite this article

share this article

Figures/Tables 8

References 27

Related Articles 1

Recommended Articles

Metrics

Comments