Improvement on Fluorine Migration from SF₆ to SiF₄ by an Efficient Mediator of Fe₂O₃/Cr₂O₃ Composites

Abstract

An economic and facile method was urgently required for the degradation of SF 6 to replace the high-energy excitation treatment. Both theoretical calculations and experimental observations were conducted to reveal the synergy of Cr/ Fe/Si composites on a new technique of SF 6 degradation through reacting silicon dioxide. Density functional theory (DFT) calculations show that strong adsorption of SF 6 on Cr 2 O 3 , and then the fast F/O exchange between CrF 3 and Fe 2 O 3 (energy barrier was 1.45 eV) as well as FeF 3 and SiO 2 (energy barrier was 1.69 eV) enhanced mediated efficiency from SF 6 to SiF 4 . The fluorine (F) migration between solid interfaces in Cr 2 O 3 &Fe 2 O 3 @SBA15 was responsible for efficient SF 6 removal. The F migration route was composed of SF 6 to CrF 3 , CrF 3 to FeF 3 , and FeF 3 to SiF 4 with the lowest thermodynamic driving. Enhanced specific accumulative converted amount (SACA) of SF 6 on Cr 2 O 3 &Fe 2 O 3 @SBA15 was achieved and the highest SACA was 13.98 mmol/g within 7 h, significantly higher than that on Fe 2 O 3 @SBA15 (5.74 mmol/g) and Cr 2 O 3 @SBA15 (2.71 mmol/g). Moreover, X-ray diffractometry and X-ray photoelectron spectroscopy were performed to support DFT calculations, including ion intensities detected using mass spectroscopy and composition analysis of the mediator during the reaction. Therefore, our work put forward a novel approach for economic and efficient SF 6 decomposition through reacting with silicon dioxide under the mediation of Cr 2 O 3 &Fe 2 O 3 . This method was also potentially used in effective degradation of refractory nonmetal halides.

Construction of LaF3 QD-modified SnS2 nanorod composites for ultrasensitive detection of H2S

“…[13][14][15][16] At present, there are relatively few studies on the detection of SF 6 decomposition products by semiconductor sensors. [17][18][19][20][21][22] Chen et al used rstprinciples to study the adsorption properties of Cu atom-modied hexagonal InN for four typical SF 6 decomposition products. 23 The results show that the Cu modied InN exhibited an enhanced adsorption of SO 2 , SOF 2 , and SO 2 F 2 gas molecules on the surface of InN.…”

Mixed-terminal MXenes react with SF6 in aqueous solution: reaction mechanism and pathway

“…Other treatments, including photodegradation, electrolytic methods, plasma methods and catalytic decomposition, are also used to remove SF 6 [5][6][7]. The use of catalysts with high efficiency and selectivity is necessary to achieve ecofriendly decomposition of SF 6 [8][9][10]. However, the removal rate and product selectivity of SF 6 have not reached the level of industrial application.…”