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Article

BaF(p-BDC)0.5 as the Catalyst Precursor for the Catalytic Dehydrochlorination of 1-Chloro-1,1-Difluoroethane to Vinylidene Fluoride

by
Shucheng Wang
1,
Chuanzhao Wang
2,
Houlin Yu
2,
Wei Yu
2,
Yongnan Liu
2,
Wucan Liu
1,
Feixiang Zhou
1,
Wanjin Yu
1,
Jiuju Wang
1,
Jianjun Zhang
1 and
Wenfeng Han
2,*
1
State Key Laboratory of Fluorinated Greenhouse Gases Replacement and Control Treatment, Zhejiang Research Institute of Chemical Industry, Tianmushan Road 387, Hangzhou 310032, Zhejiang, China
2
Institute of Industrial Catalysis, Zhejiang University of Technology, Chaowang Road 18, Hangzhou 310014, Zhejiang, China
*
Author to whom correspondence should be addressed.
Catalysts 2021, 11(11), 1268; https://0-doi-org.brum.beds.ac.uk/10.3390/catal11111268
Submission received: 17 September 2021 / Revised: 15 October 2021 / Accepted: 18 October 2021 / Published: 21 October 2021
(This article belongs to the Special Issue Nanocatalysis for Green Chemicals Synthesis)
Browse Figures
Versions Notes

Abstract

:
A BaF(p-BDC)0.5 catalyst was prepared by solid state reaction at room temperature with Ba(OH)2 as precursor, NH4F as F source, and H2(p-BDC) as organic ligand. The calcined samples were used as catalysts for dehydrochlorination of 1-chloro-1,1-difluoroethane to generate vinylidene fluoride (VDF) at 350 °C. Commercial production of VDF is carried out at 600–700 °C. Clearly, pyrolysis of the BaF(p-BDC)0.5 catalyst provided a promising way to prepare VDF at low temperatures. Prior to calcination, the activity of the BaF(p-BDC)0.5 catalyst was low. Following calcination at high temperatures, BaF(p-BDC)0.5 decomposed to BaF2 and BaCO3, and then the catalyst was chlorinated and fluorinated to BaClF, which showed high activity and stable VDF selectivity for dehydrochlorination of 1-Chloro-1,1-Difluoroethane to VDF.

1. Introduction

1,1-difluoroethylene (VDF) is a key monomer for the production of various resins, rubbers, and coatings [1,2]. Poly vinylidene fluorides (PVDF) prepared by VDF or co-polymers present chemical resistance, high temperature stability, oxidation resistance, weather resistance, piezoelectric, dielectric, and thermoelectric properties. Hence, they are widely applied in petrochemical, electronic, and electrical fields as well as fluorocarbon coatings. Recently, PVDF was confirmed to be promising material for the development of novel devices, such as sensors and electrolytes. Ferroelectric polymers function as prime candidates for sensors improving compactness and efficiency of the devices because of their multifunctionality [3,4]. PVDF is also one of the components in polymer electrolytes for sodium battery with high safety, suppression of sodium dendrite formation, and reduced electrolyte decomposition [5]. Consequently, the worldwide demand for VDF and PVDF is growing significantly. The production capacity ranks the second position among all the fluorinated polymers with 53,000 tons per year, only slightly lower than PTFE (Poly tetrafluoroethylene).
Although VDF can be produced via the dehydrofluorination of 1,1,1-trifluoroethane (HFC-143a) [6] or via simple co-pyrolysis of CHF3 with CH4 at elevated temperatures [7,8,9], the reaction conditions are rather harsh. Similarly, the co-pyrolysis of chlorodifluoromethane (HCFC-22) and methane also leads to the formation of VDF [10]. Although these routes use inexpensive feedstocks, the yield and selectivity to VDF is low which are far from industrial application.
Currently, VDF is produced via the decomposition (dehydrochlorination) of HCFC-142b (1-Chloro-1,1-Difluoroethane) at high temperatures (>650 °C) in the industry [1]. Unfortunately, due to the carbon deposition at elevated temperatures, the tube reactor tends to be blocked. Consequently, the reactor has to be cut off to remove coke, which significantly inhibits the efficiency of continuous production. Clearly, a catalyst which operates the pyrolysis of HCFC-142b at low temperatures is highly desired. Besides, efficient catalysts of dehydrochlorination also facilitate the preparation of other halogenated olefins, such as 1,1-dichloroethylene (VDC), vinyl chloride monomer (VCM), 2,3,3-tetrafluoropropylene (HFO-1234yf) [11,12,13,14].
For the reaction of HCFC-142b dehydrochlorination, the formation of extremely corrosive HCl and HF poses great challenge for the development of proper catalysts. Hence, the selection of catalysts materials is limited. Initially, we explored series of nitrogen doped carbon materials as the catalysts since they are inert to the corrosion of HCl and HF. It was found that the reaction temperature can be reduced from 650 °C to 350 °C in the presence of catalysts, which is beneficial to save energy and avoid coking in the reaction process [15,16]. Although N-doped activated carbon and mesoporous carbon exhibit moderate conversion and high selectivity to VDF, they are difficult to be recovered after coking and deactivation. Hence, it is still necessary to develop more effective catalysts to combine high catalytic performance and recyclability.
Therefore, we investigated series of metal fluorides, such as AlF3, SrF2, BaF2 as the catalysts [17]. Among various metal fluorides, SrF2 has high activity for cleavage of HCFC-142b to VDF, but its selectivity is low [18,19]. In addition, BaF2 also shows high activity in this reaction, and the selectivity to VDF is 95% [20]. However, during the dehydrochlorination reaction, BaF2 tends to be chlorinated by F species to BaClF under the reaction conditions [21]. If BaClF continues to be chlorinated to BaCl2, the conversion of HCFC-142b will be significantly reduced.
In this paper, the BaF(p-BDC)0.5 catalyst, barium fluoride connected with the framework of terephthalic acid was prepared via solid-state grinding at room temperature. The catalysts were calcined at different temperatures and the corresponding catalytic performance for the dehydrochlorination of 1-chloro-1,1-difluoroethane reaction over the catalysts were systematically evaluated.

2. Results

The catalytic performance of BaF(p-BDC)0.5 and the calcinated catalysts for the dehydrochlorination of 1-chloro-1,1-difluoroethane (CH3CClF2, HCFC-142b) to vinylidene fluoride (VDF, CH2=CF2) under atmospheric pressure is illustrated in Figure 1. As depicted in Figure 1, the BaF(p-BDC)0.5 possesses poor activity for the dehydrochlorination of HCFC-142b with conversion lower than 10% and selectivity to VDF of about 82%. Following the calcination of BaF(p-BDC)0.5 at 500 °C, the activity of the catalyst (BaF(p-BDC)0.5-M500) is only slightly improved. By contrast, the selectivity to VDF is significantly improved, enhanced from 82 to 91%. After being calcinated at 600 and 700 °C, the activities of the catalysts (BaF(p-BDC)0.5-M600 and BaF(p-BDC)0.5-M700) are improved. The conversion of HCFC-142b is higher than 30% with selectivity to VDF higher than 90% which is significantly higher than BaF2 or SrF2 catalysts [18,19,21]. With further calcination at 800 °C, both the conversion of HCFC-142b and selectivity to VDF over the BaF(p-BDC)0.5-M800 are dramatically lower than that of BaF(p-BDC)0.5-M600 and BaF(p-BDC)0.5-M700. In addition, all the catalysts gradually deactivate after the induction period, and the selectivity to VDF is well maintained.
As mentioned in our previous study [15,21], for BaF2, the reason for deactivation during dehydrochlorination is that the catalyst reacts with HCl generated in the reaction, and then the element F on the catalyst is further replaced by Cl. In addition to carbon deposition, this is the main cause of deactivation. It is worth noting that the effect of carbon deposition on the activity of the catalyst was minor within the time on stream investigated. Calcination of BaF2 is a simple method to reduce its deactivation. However, it is very sensitive for BaF2 calcinated at high temperatures, and its activity is greatly reduced due to obvious sintering when calcined at above 600 °C (Figure 1a). Different from BaF2 prepared by precipitation, BaF2 obtained by calcination and decomposition of BaF(p-BDC)0.5 exhibits enhanced catalytic performance.
Clearly, BaF(p-BDC)0.5 presents promising catalytic performance for the dehydrochlorination reaction. The doping of p-BDC to BaF2 plays a positive role in the catalytic activity. Hence, the catalysts were characterized in detail. Determined by N2 adsorption and desorption, the specific surface areas of all catalyst samples are rather low (<1 m2/g). We suggest that the specific surface play a minor role in the performance differences of catalysts.
BaF(p-BDC)0.5 was facilely prepared by solid state reaction of Ba(OH)2·8H2O with NH4F/PTA at room temperature [22]. As shown in Figure 2a, the XRD spectrum of BaF(p-BDC)0.5 agrees well with the report of Breitfeld [22]. Clearly, BaF(p-BDC)0.5 was achieved successfully. Following calcination at 500 °C, the intensities of diffraction peak are enhanced. However, no other new impurities are identified in Figure 2a. However, when the calcination temperature was increased to 600 °C, as shown in Figure 2b, the specific diffraction peaks assigned to BaF(p-BDC)0.5 disappears, and instead, the characteristic peaks ascribed to BaCO3 and BaF2 are presented. Moreover, elevated calcination temperature facilitates the complete decomposition of BaF(p-BDC)0.5 to BaCO3 and BaF2, as well as the interaction between BaCO3 and BaF2, which means that the initial activity of the BaF(p-BDC)0.5-M600, BaF(p-BDC)0.5-M700, and BaF(p-BDC)0.5-M800 catalysts (Figure 1) originated from the synergistic effect of BaCO3 and BaF2.
With BaF(p-BDC)0.5-M600, BaF(p-BDC)0.5-M700 and BaF(p-BDC)0.5-M800 as catalysts, there exists an induction period (Figure 1). In order to clarify the true active species for dehydrochlorination, BaF(p-BDC)0.5-M600 samples with different reaction time were selected, and the XRD patterns are shown in Figure 2c. After time on stream of 2 h, the catalyst exhibits the highest activity, and the phase of the catalyst is composed of pure BaClF, which confirms that BaClF is the efficient component for the reaction [21]. Following the reaction time extends from 2 to 12 h, the conversion of HCFC-142b declines from 50 to 38%, and meantime, the phase of the catalyst changes from pure BaClF to the mixture of BaClF and BaCl2. As reported previously, BaCl2 presents low activity for dehydrochlorination. As a result, it is suggested that the increase in activity is ascribed to the fluorination as well as chlorination of BaF2 and BaCO3 to BaClF, while BaClF is inevitable to be further chlorinated to BaCl2, leading to the decrease in activity. In addition, the XRD diffraction of used BaF(p-BDC)0.5-M700 and BaF(p-BDC)0.5-M800 further reinforces the conclusion. As shown in Figure 2d, after time on stream of 12 h, the characteristic peak attributed to BaCl2 could be found in the catalysts, but the diffraction intensity of used BaF(p-BDC)0.5-M800 is much weaker.
The obtained catalysts were further investigated by XPS (Figure 3). It is noticed that the binding energy of Ba 3d5/2 in BaF(p-DC)0.5 decreases by 0.4 eV following calcination from 400 to 600 °C. The binding energy of Ba 3d5/2 in BaF(p-BDC)0.5-M600, BaF(p-BDC)0.5-M700 and BaF(p-BDC)0.5-M800 are all around 779.80 eV, which is the typical binding energy of Ba 3d5/2 in BaF2 and BaCO3 [23]. Combined with the activity diagram and XRD characterization of the catalyst, it could be confirmed that BaF(p-BDC)0.5 gradually decomposes after calcination at 400–600 °C, and could be completely decomposed to BaCO3 and BaF2 at 600 °C. In addition, the shift of Ba 3d5/2 binding energy indicates the strong interaction between Ba and carbon residuals derived from the decomposition of p-BDC. Clearly, this interaction contributes to the improvement of catalytic activity and stability [18].
Figure 4 exhibited the SEM images of the calcinated catalysts. For BaF(p-BDC)0.5-M500, irregular particles were obtained after calcination. The average size of the catalyst is ca. 500 nm. With the increase in calcination temperature, the size of the grains becomes more uneven but are still accompanied with small particles. With the calcination temperature being increased to 700 °C, the particle size aggregated up to 2 μm. Meantime, the particles turn more dense, indicating the occurrence of sintering. As expected, with further increase in calcination temperature to 800 °C, larger particles could be obtained. Then, it is reasonable to deduce that the inferior catalytic performance of BaF(p-BDC)0.5-M700 and BaF(p-BDC)0.5-M800 compared with BaF(p-BDC)0.5-M600 results from the larger grain size.
Before the reaction, the average grain sizes of BaF(p-BDC)0.5-M600, BaF(p-BDC)0.5-M700 and BaF(p-BDC)0.5-M800 were 82.5, 116.1, and 164.5 nm, respectively. After the reaction, the grain size of the specific catalysts were 159.4, 191.4, and 257.9 nm, respectively. After 2 h of reaction, the BaF(p-BDC)0.5-M600 was composed by BaClF, with a grain size of 55.1 nm. After 12 h of reaction, the grain size of BaF(p-BDC)0.5-M600 (BaClF) is 159.4 nm (Figure 5). Clearly, the grain size of the catalyst increases significantly.
In order to further verify the effect of crystal size on the catalytic performance, the crystal size of fresh and used catalysts calcinated at 400–800 °C are compared. The crystal sizes are determined by the Scherrer equation based on XRD [24].
The crystal sizes of BaF(p-BDC)0.5 catalysts calcined in air at 400, 500, 600, 700, and 800 °C are illustrated in Figure 6. Before the reaction, the crystal sizes of BaF(p-BDC)0.5 calcined at different temperatures are 21.8, 43.0, 82.5, 116.1, and 164.5 nm, respectively. After reaction, the crystal sizes of the catalyst are 29.4, 53.8, 159.4, 191.4, and 257.9 nm, respectively. It is found that the higher the calcination temperature is, the more serious the sintering is. Low calcination temperature of BaF(p-BDC)0.5 is beneficial to the disordered structure of BaF(p-BDC)0.5. By comparing the crystal size of the catalyst before and after the reaction, although the reaction was carried out at 350 °C, it is found that the crystal size of the catalyst increases significantly, and its influence is more significant than that of calcination at high temperatures. This indicates that the crystal size of the catalyst increases obviously when the catalyst is chlorinated during the reaction, which indicates that the structure and phase state of the catalyst have changed significantly.
As indicated in Figure 2b, BaCO3 is derived during the calcination of BaF(p-BDC)0.5. To elucidate the synergism of BaCO3 to the BaF2 catalyst, additional experiments were carried out. Through combining the results of XRD and XPS, it could evidence that the composition of the BaF(p-BDC)0.5-M600 is BaF2 and BaCO3. Then, in order to understand the synergism between BaCO3 and BaF2, the catalytic activities were compared for BaCO3 annealed at 600 °C (BaCO3-M600), BaF2 (BaF2-M600) and BaF(p-BDC)0.5-M600. As shown in Figure 7, the HCFC-142b conversion over BaF2-M600 was the lowest, but the selectivity to VDF is high. By contrast, BaCO3-M600 exhibits higher activity for HCFC-142b conversion, but the selectivity of VDF is lower than BaF2-M600. Then, as expected, BaF(p-BDC)0.5-M600 constituted by BaCO3 and BaF2, could maintain the merits of BaCO3 and BaF2 exhibiting relatively high HCFC-142 conversion and VDF selectivity. Besides, from Figure 2c, we suggest that the active species of BaF(p-BDC)0.5-M600 was BaClF. However, the pure BaClF calcinated at 600 °C (BaClF-M600) shows lower activity than BaF(p-BDC)0.5-M600, which could further support the cooperation between BaCO3 and BaF2. The change of BaF2 during the reaction was investigated by our previous report [21], BaF2 was confirmed to be turned into BaCl2 leading to the deactivation of the catalysts. The transformation process of BaCO3 is identical with BaF2 (Figure 7c,d) as well as BaF(p-BDC)0.5-M600.

3. Materials and Methods

3.1. Preparation of Catalysts

Ba(OH)2·8H2O and NH4F were selected as Ba and F sources, respectively. PTA(terephthalic acid) was adopted as organic ligands. Firstly, 0.05 mol NH4F and 0.025 mol PTA were added to the mortar rigorously for 0.5 h. Afterward, 0.05 mol Ba(OH)2·8H2O powder was added to the above mixture with grinding for another 1 h. Within the reaction of the mixture, NH3 was generated and crystal water released. Then, the mixture was treated under 110 °C for 5 h to produce the BaF(p-BDC)0.5. It is to be noted that all the raw materials were obtained from Aladdin Co. (Shanghai, China) without further purification Then the samples were calcined in a muffle furnace at different temperatures (400~800 °C) for 5 h to obtain the catalyst; they were recorded as BaF(p-BDC)0.5-M400, BaF(p-BDC)0.5-M500, BaF(p-BDC)0.5-M600, BaF(p-BDC)0.5-M700 and BaF(p-BDC)0.5-M800. In addition, the regents used in the work were all get from Aladdin, Shanghai, China without other treatment.

3.2. Catalytic Activity

The catalytic activity evaluation was conducted in a fixed-bed reactor (i.d. = 22 mm). Firstly, the prepared Ba-based catalysts (2 mL) was loaded to the isothermal zone of the reactor. Then, the mixture of HCFC-142b (20 mL min−1) and N2 (20 mL min−1) was introduced to the reactor, accordingly. The gas hourly space velocity (GHSV) was maintained at 1200 h−1. The reactions were carried out at 350 °C, and the reaction temperature of the catalysts layer was confirmed by inserting a thermal couple into the middle of the catalyst bed. Owing to the outlet gases possibly containing HCl and HF, KOH solution (1 mol/L) was used to remove the acid gas. A gas chromatograph (GC-1690 JieDao, Hangzhou, China) equipped with a thermal conductivity detector (TCD, Hangzhou, China) was used to analyze the gas composition. As noted, blank experiments showed that no VF was detected without catalysts at 350 °C.

3.3. Catalyst Characterization

The phase compositions of the synthesized catalysts were confirmed by X-ray diffraction (XRD) experiments, performed with the X’Pert Pro analytical instrument (Almelo, Overijssel, The Netherlands). The chemical states of Ba species were analyzed via X-Ray photoelectron spectroscopy (XPS) spectra, conducted on the Thermo EscaLab 250Xi (Cambridge, Waltham, MA, USA), equipped with monochromatized Al Kα X-ray (1486.6 eV). The binding energy values were corrected by C1s line at 284.5 eV. The morphologies of the Ba-based catalysts were obtained by scanning electron microscopy (SEM), carried out with Helios G4 CX (Cambridge, Waltham, MA, USA).

4. Conclusions

BaF(p-BDC)0.5 catalysts were successfully prepared via the solid-state reaction method at room temperature. BaF2 and BaCO3 were obtained after calcination at high temperature, which promotes the pyrolysis of HCFC-142b (CH3CClF2) to VDF (CH2=CF2) at 350 °C. The reaction temperature was significantly lower than the industrial manufacturing temperature (600–700 °C) by the thermal decomposition of HCFC-142b. In the reaction, BaF2 and BaCO3 were chlorinated to BaClF, which is the active species in this reaction. The pyrolysis of BaF(p-BDC)0.5 forms the mixture of BaF2 and BaCO3 and then BaClF with small crystal size was derived during the reaction, exhibiting high activity for dehydrochlorination of HCFC-142b.

Author Contributions

Conceptualization, W.H.; methodology, W.H.; formal analysis, C.W. and H.Y.; investigation, C.W., H.Y., W.Y. (Wei Yu) and Y.L.; resources, S.W.; data curation, C.W., H.Y., W.Y. (Wei Yu), F.Z., W.Y. (Wanjin Yu), J.W. and Y.L.; writing—original draft preparation, W.Y. (Wei Yu) and W.H.; writing—review and editing, W.H.; supervision, W.H., W.L. and J.Z.; project administration, W.H.; funding acquisition, W.H., W.L. and J.Z. All authors have read and agreed to the published version of the manuscript.

Funding

This research was funded by the Zhejiang Provincial Natural Science Foundation of China under grant no. LY19B060009 and National Key Research and Development Project of China (2019YFC0214504). The authors also gratefully acknowledge the financial support from the State Key Laboratory of Green Chemistry Synthesis Technology (GCST-20200006).

Conflicts of Interest

The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.

References

  1. Ameduri, B. From Vinylidene Fluoride (VDF) to the Applications of VDF-Containing Polymers and Copolymers: Recent Developments and Future Trends. Chem. Rev. 2009, 109, 6632–6686. [Google Scholar] [CrossRef] [Green Version]
  2. Li, D.H.; Qi, S.C.; Zhang, X.A.; Liao, M.Y. Preparation, Functionalization and Properties of Low Molecular Fluoropolymers. Prog. Chem. 2016, 28, 673–685. [Google Scholar] [CrossRef]
  3. Stadlober, B.; Zirkl, M.; Irimia-Vladu, M. Route towards sustainable smart sensors: Ferroelectric polyvinylidene fluoride-based materials and their integration in flexible electronics. Chem. Soc. Rev. 2019, 48, 1787–1825. [Google Scholar] [CrossRef]
  4. Hu, X.P.; Che, Y.P.; Zhang, Z.J.; Shen, Q.D.; Chu, B.J. BiFeO3-BaTiO3/P(VDF-TrFE) Multifunctional Polymer Nanocomposites. ACS Appl. Electron. Mater. 2021, 3, 743–751. [Google Scholar] [CrossRef]
  5. Yang, J.F.; Zhang, H.R.; Zhou, Q.; Qu, H.T.; Dong, T.T.; Zhang, M.; Tang, B.; Zhang, J.J.; Cui, G.L. Safety-Enhanced Polymer Electrolytes for Sodium Batteries: Recent Progress and Perspectives. ACS Appl. Mater. Interfaces 2019, 11, 17109–17127. [Google Scholar] [CrossRef]
  6. Han, W.; Zhang, C.; Wang, H.; Zhou, S.; Tang, H.; Yang, L.; Wang, Z. Sub-nano MgF2 embedded in carbon nanofibers and electrospun MgF2 nanofibers by one-step electrospinning as highly efficient catalysts for 1,1,1-trifluoroethane dehydrofluorination. Catal. Sci. Technol. 2017, 7, 6000–6012. [Google Scholar] [CrossRef]
  7. Cheng, Y.M.; Wang, J.C.; Han, W.F.; Song, Y.Y.; Liu, W.C.; Yang, L.T.; Wang, S.C.; Wu, Z.X.; Tang, H.D.; Zhang, J.J.; et al. Catalytic coupling of CH4 with CHF3 for the synthesis of VDF over LaOF catalyst. Greenh. Gases 2018, 8, 587–602. [Google Scholar] [CrossRef]
  8. Han, W.; Song, Y.; Liu, W.; Yang, L.; Tang, H.; Wang, S.; Wu, Z.; Zhang, J. Promotion of O2 on the co-pyrolysis of CHF3 and CH4 for VDF synthesis. Greenh. Gases Sci. Technol. 2017, 7, 891–902. [Google Scholar] [CrossRef]
  9. Han, W.; Li, Y.; Tang, H.; Liu, H. Treatment of the potent greenhouse gas, CHF3—An overview. J. Fluor. Chem. 2012, 140, 7–16. [Google Scholar] [CrossRef]
  10. Han, W.F.; Kennedy, E.M.; Mackie, J.C.; Dlugogorski, B.Z. Synthesis of Vinylidene Fluoride via Reaction of Chlorodifluoromethane (HCFC-22) with Methane. Ind. Eng. Chem. Res. 2010, 49, 6010–6019. [Google Scholar] [CrossRef]
  11. Chen, C.; Shen, Z.B.; Zhu, Y.P.; Wang, F.; Jiang, B.; Qi, H.M. Construction of activated carbon-supported B3N3 doped carbon as metal-free catalyst for dehydrochlorination of 1,2-dichloroethane to produce vinyl chloride. RSC Adv. 2021, 11, 183–191. [Google Scholar] [CrossRef]
  12. Zhang, P.Z.; Jiang, Z.B.; Cui, Y.H.; Xie, G.Q.; Jin, Y.Z.; Guo, L.L.; Xu, Y.Q.; Zhang, Q.F.; Li, X.N. Catalytic performance of ionic liquid for dehydrochlorination reaction: Excellent activity and unparalled stability. Appl. Catal. B 2019, 255, 117757. [Google Scholar] [CrossRef]
  13. Tian, S.; Mao, W.; Sun, P.F.; Dang, J.S.; Zhou, L.; Lu, J.; Kemnitz, E. Breakthrough synthesis of 2,3,3,3-tetrafluoropropene via hydrogen-assisted selective dehydrochlorination of 1,1,1,2-tetrafluoro-2-chloropropane over nickel phosphides. J. Catal. 2020, 391, 366–377. [Google Scholar] [CrossRef]
  14. Yuan, J.J.; Hong, Z.; Xi, Z.W.; Jia, W.Z.; Huang, Z.; Li, J.H.; Zhu, Z.R. Catalytic Pyrolysis of 2-Chloro-1,1-difluoroethane to Synthesize Vinylidene Fluoride over the Potassium-Promoted Carbon Catalysts. ChemistrySelect 2020, 5, 5788–5793. [Google Scholar] [CrossRef]
  15. Wang, Z.K.; Han, W.F.; Zhang, C.P.; Zhou, S.L.; Wang, H.L.; Tang, H.D.; Liu, H.Z. Preparation of N-Doped Activated Carbon for Catalytic Pyrolysis of 1-Chloro-1,1-difluoroethane to Vinylidene Fluoride. ChemistrySelect 2018, 3, 1015–1018. [Google Scholar] [CrossRef]
  16. Wang, Z.K.; Han, W.F.; Tang, H.D.; Li, Y.; Liu, H.Z. Preparation of N-doped ordered mesoporous carbon and catalytic performance for the pyrolysis of 1-chloro-1,1-difluoroethane to vinylidene fluoride. Microporous Mesoporous Mat. 2019, 275, 200–206. [Google Scholar] [CrossRef]
  17. Han, W.F.; Liu, B.; Kang, Y.K.; Wang, Z.K.; Yu, W.; Yang, H.; Liu, Y.N.; Lu, J.Q.; Tang, H.D.; Li, Y.; et al. Experimental and DFT Mechanistic Study of Dehydrohalogenation of 1-Chloro-1,1-difluoroethane over Metal Fluorides. Ind. Eng. Chem. Res. 2019, 58, 18149–18159. [Google Scholar] [CrossRef]
  18. Liu, W.C.; Liu, Y.N.; Mardochee, K.M.; Wang, Z.K.; Wang, S.C.; Yu, W.; Zhang, J.J.; Han, W.F. Selectivity Dependence of 1,1-Difluoro-1-Chloroethane Dehydrohalogenation on the Metal-Support Interaction over SrF2 Catalyst. Catalysts 2020, 10, 355. [Google Scholar] [CrossRef] [Green Version]
  19. Wang, Z.K.; Han, W.F.; Liu, H.Z. EDTA-assisted hydrothermal synthesis of cubic SrF2 particles and their catalytic performance for the pyrolysis of 1-chloro-1,1-difluoroethane to vinylidene fluoride. CrystEngComm 2019, 21, 1691–1700. [Google Scholar] [CrossRef]
  20. Wang, Z.K.; Han, W.F.; Tang, H.D.; Liu, H.Z. CaBaFx composite as robust catalyst for the pyrolysis of 1-chloro-1,1-difluoroethane to vinylidene fluoride. Catal. Commun. 2019, 120, 42–45. [Google Scholar] [CrossRef]
  21. Yu, W.; Han, W.F.; Liu, Y.N.; Lu, J.Q.; Yang, H.; Liu, B.; Tang, H.D.; Chen, A.M.; Li, Y. Facile Preparation of BaClxFy for the Catalytic Dehydrochlorination of 1-Chloro-1,1-Difluoroethane to Vinylidene Fluoride. Catalysts 2020, 10, 377. [Google Scholar] [CrossRef] [Green Version]
  22. Breitfeld, S.; Scholz, G.; Emmerling, F.; Kemnitz, E. BaF-benzenedicarboxylate: The first mechanochemical synthesis of a new coordination polymer with a direct Ba-F bond. J. Mater. Sci. 2018, 53, 13682–13689. [Google Scholar] [CrossRef]
  23. Gauzzi, A.; Mathieu, H.J.; James, J.H.; Kellett, B. AES, XPS and SIMS characterization of YBa2Cu3O7 superconducting high-tc thin-films. Vacuum 1990, 41, 870–874. [Google Scholar] [CrossRef]
  24. He, K.; Chen, N.; Wang, C.; Wei, L.; Chen, J. Method for Determining Crystal Grain Size by X-Ray Diffraction. Cryst. Res. Technol. 2018, 53, 1700157. [Google Scholar] [CrossRef]
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Figure 1. Catalytic performance of the BaF(p-BDC)0.5 catalysts for the pyrolysis of HCFC-142b as a function of time on stream at atmospheric pressure, a gas hourly space velocity (GHSV) of 1200 h−1, and a reaction temperature of 350 °C. (a) Conversion of HCFC-142b, (b) Selectivity to vinylidene fluoride (VDF).
Figure 1. Catalytic performance of the BaF(p-BDC)0.5 catalysts for the pyrolysis of HCFC-142b as a function of time on stream at atmospheric pressure, a gas hourly space velocity (GHSV) of 1200 h−1, and a reaction temperature of 350 °C. (a) Conversion of HCFC-142b, (b) Selectivity to vinylidene fluoride (VDF).
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Figure 2. XRD patterns of fresh (a,b) and used catalysts (c,d), respectively.
Figure 2. XRD patterns of fresh (a,b) and used catalysts (c,d), respectively.
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Figure 3. Ba 3d XPS spectra of calcinated BaF(p-BDC)0.5 catalysts.
Figure 3. Ba 3d XPS spectra of calcinated BaF(p-BDC)0.5 catalysts.
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Figure 4. SEM images of (a) BaF(p-BDC)0.5-M500, (b) BaF(p-BDC)0.5-M600, (c) BaF(p-BDC)0.5-M700, (d) BaF(p-BDC)0.5-M800. The scale bar of (a–d) are 1 μm, 1 μm, 4 μm and 4 μm, respectively.
Figure 4. SEM images of (a) BaF(p-BDC)0.5-M500, (b) BaF(p-BDC)0.5-M600, (c) BaF(p-BDC)0.5-M700, (d) BaF(p-BDC)0.5-M800. The scale bar of (a–d) are 1 μm, 1 μm, 4 μm and 4 μm, respectively.
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Figure 5. SEM images of (a) spent BaF(p-BDC)0.5-M500, (b) spent BaF(p-BDC)0.5-M600, (c) spent BaF(p-BDC)0.5-M700, (d) spent BaF(p-BDC)0.5-M800. The scale bar of (a–d) are 1 μm, 1 μm, 2 μm and 4 μm, respectively.
Figure 5. SEM images of (a) spent BaF(p-BDC)0.5-M500, (b) spent BaF(p-BDC)0.5-M600, (c) spent BaF(p-BDC)0.5-M700, (d) spent BaF(p-BDC)0.5-M800. The scale bar of (a–d) are 1 μm, 1 μm, 2 μm and 4 μm, respectively.
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Figure 6. The crystal size of fresh and used catalysts.
Figure 6. The crystal size of fresh and used catalysts.
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Figure 7. Catalytic performance of BaF(p-BDC)0.5-M600, BaF2-M600, BaCO3-M600, and BaClF-M600 catalysts for the dechlorination of HCFC-142b as a function of time on stream at atmospheric pressure, a gas hourly space velocity (GHSV) of 1200 h−1, and a reaction temperature of 350 °C. (a) Conversion of HCFC-142b, (b) Selectivity to vinylidene fluoride (VDF); XRD patterns of fresh (c) and used BaCO3 catalysts (d).
Figure 7. Catalytic performance of BaF(p-BDC)0.5-M600, BaF2-M600, BaCO3-M600, and BaClF-M600 catalysts for the dechlorination of HCFC-142b as a function of time on stream at atmospheric pressure, a gas hourly space velocity (GHSV) of 1200 h−1, and a reaction temperature of 350 °C. (a) Conversion of HCFC-142b, (b) Selectivity to vinylidene fluoride (VDF); XRD patterns of fresh (c) and used BaCO3 catalysts (d).
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Wang, S.; Wang, C.; Yu, H.; Yu, W.; Liu, Y.; Liu, W.; Zhou, F.; Yu, W.; Wang, J.; Zhang, J.; et al. BaF(p-BDC)0.5 as the Catalyst Precursor for the Catalytic Dehydrochlorination of 1-Chloro-1,1-Difluoroethane to Vinylidene Fluoride. Catalysts 2021, 11, 1268. https://0-doi-org.brum.beds.ac.uk/10.3390/catal11111268

AMA Style

Wang S, Wang C, Yu H, Yu W, Liu Y, Liu W, Zhou F, Yu W, Wang J, Zhang J, et al. BaF(p-BDC)0.5 as the Catalyst Precursor for the Catalytic Dehydrochlorination of 1-Chloro-1,1-Difluoroethane to Vinylidene Fluoride. Catalysts. 2021; 11(11):1268. https://0-doi-org.brum.beds.ac.uk/10.3390/catal11111268

Chicago/Turabian Style

Wang, Shucheng, Chuanzhao Wang, Houlin Yu, Wei Yu, Yongnan Liu, Wucan Liu, Feixiang Zhou, Wanjin Yu, Jiuju Wang, Jianjun Zhang, and et al. 2021. "BaF(p-BDC)0.5 as the Catalyst Precursor for the Catalytic Dehydrochlorination of 1-Chloro-1,1-Difluoroethane to Vinylidene Fluoride" Catalysts 11, no. 11: 1268. https://0-doi-org.brum.beds.ac.uk/10.3390/catal11111268

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