Oxidative coupling of methane by Mn-Na₂WO₄/γ-Al₂O₃ catalyst: effect of Mn/W ratio

Abstract

In this study, Mn-Na₂WO₄/γ-Al₂O₃ catalysts with varying ratios of Mn/W were prepared using the dry impregnation method. These catalysts were then tested for their suitability in the oxidative coupling of methane reaction. The X-ray photoelectron results revealed the presence of the tetrahedral WO₄^2– phase in all prepared catalysts. It is believed that the presence of this phase is associated with high catalyst activity, indicating the potential of the catalysts for the desired reaction. The activity results show that the catalyst with a high Mn/W ratio exhibited higher activity at 800 °C, whereas the catalyst with a low Mn/W ratio showed greater activity at 850 °C. This suggests that the Mn/W ratio influences the reaction temperature at which the catalyst is most active. Furthermore, the X-ray diffraction results of the treated catalysts revealed that the catalyst with a high Mn/W ratio exhibited more MnAl₂O₄ at 800 °C, whereas the catalyst with a low Mn/W ratio contained more MnWO₄ at 850 °C. The results suggest that the presence of MnAl₂O₄ sites may promote a more facile Mn²⁺ ↔ Mn³⁺ cycle at lower temperatures than the MnWO₄ site, potentially contributing to the enhanced catalyst activity in the oxidative coupling of methane reaction at 800 °C.

Key words： oxidative coupling of methane; Mn-Na₂WO₄; methane; Al₂O₃

Competing interests

The authors declare that they have no competing interests.

Acknowledgements

The authors of this work appreciate the financial support of the Ferdowsi University of Mashhad Research Council, Mashhad, Iran (Grant No. 68841) and (OCM project No. 23346).

References

1 Heilig G K . The greenhouse gas methane (CH₄): sources and sinks, the impact of population growth, possible interventions. Population and Environment, 1994, 16(2): 109–137

2 Eren T , Polat C . Natural gas underground storage and oil recovery with horizontal wells. Journal of Petroleum Science Engineering, 2020, 187: 106753

3 Karakaya C , Kee R J . Progress in the direct catalytic conversion of methane to fuels and chemicals. Progress in Energy and Combustion Science, 2016, 55: 60–97

4 Mousavi M , Nakhaei Pour A . Performance and structural features of LaNi_0.5Co_0.5O₃ perovskite oxides for the dry reforming of methane: influence of the preparation method. New Journal of Chemistry, 2019, 43(27): 10763–10773

5 Nakhaei Pour A , Housaindokht M R , Kamali Shahri S M . Fischer-Tropsch synthesis over cobalt/CNTs catalysts: functionalized support and catalyst preparation effect on activity and kinetic parameters. Industrial & Engineering Chemistry Research, 2018, 57(41): 13639–13649

6 Nakhaei Pour A , Karimi J , Taghipoor S , Gholizadeh M , Hashemian M . Fischer-Tropsch synthesis over CNT-supported cobalt catalyst: effect of magnetic field. Journal of the Indian Chemical Society, 2017, 14(7): 1477–1488

7 Behrooz M , Peyrovi M H , Nakhaei Pour A . Direct partial oxidation (dpo) of methane to higher hydrocarbons by modified h-Zsm5 catalyst. Reaction Kinetics and Catalysis Letters, 2001, 73(1): 127–133

8 Liu Y , Osta E H , Poryvaev A S , Fedin M V , Longo A , Nefedov A , Kosinov N . Direct conversion of methane to zeolite-templated carbons, light hydrocarbons, and hydrogen. Carbon, 2023, 201: 535–541

9 Nakhaei Pour A , Housaindokht M R . A new kinetic model for direct CO₂ hydrogenation to higher hydrocarbons on a precipitated iron catalyst: effect of catalyst particle size. Journal of Energy Chemistry, 2017, 26(3): 359–367

10 Gambo Y , Jalil A , Triwahyono S , Abdulrasheed A . Recent advances and future prospect in catalysts for oxidative coupling of methane to ethylene: a review. Journal of Industrial and Engineering Chemistry, 2018, 59: 218–229

11 Ortiz-Bravo C A , Chagas C A , Toniolo F S . Oxidative coupling of methane (OCM): an overview of the challenges and opportunities for developing new technologies. Journal of Natural Gas Science and Engineering, 2021, 96: 104254

12 Karakaya C , Zhu H , Loebick C , Weissman J G , Kee R J . A detailed reaction mechanism for oxidative coupling of methane over Mn/Na₂WO₄/SiO₂ catalyst for non-isothermal conditions. Catalysis Today, 2018, 312: 10–22

13 Sourav S , Wang Y , Kiani D , Baltrusaitis J , Fushimi R R , Wachs I E . New mechanistic and reaction pathway insights for oxidative coupling of methane (OCM) over supported Na₂WO₄/SiO₂ catalysts. Angewandte Chemie International Edition, 2021, 60(39): 21502–21511

14 Wu J , Li S , Niu J , Fang X . Mechanistic study of oxidative coupling of methane over Mn₂O₃-Na₂WO₄SiO₂ catalyst. Applied Catalysis A, General, 1995, 124(1): 9–18

15 Zhao G , Ni J , Si J , Sun W , Lu Y . Low-temperature light-off MnO_x-Na₂WO₄-based catalysts: a step forward to OCM process industrialization. ChemPhysChem, 2022, 23(22): e202200365

16 Gu S , Kang J , Lee T , Shim J , Choi J W , Suh D J , Lee H , Yoo C , Baik H , Choi J , Ha J M . Na₂WO₄/Mn supported on all-silica delaminated zeolite for the optimal oxidative coupling of methane via the effective stabilization of tetrahedral WO₄: elucidating effects of support precursors with different crystal structures, Al-addition, and morphologies. Chemical Engineering Journal, 2023, 457: 141057

17 Jaroenpanon K , Tiyatha W , Chukeaw T , Sringam S , Witoon T , Wattanakit C , Chareonpanich M , Faungnawakij K , Seubsai A . Synthesis of Na₂WO₄-Mn_xO_y supported on SiO₂ or La₂O₃ as fiber catalysts by electrospinning for oxidative coupling of methane. Arabian Journal of Chemistry, 2022, 15(2): 103577

18 Shahri S M K , Nakhaei Pour A . Ce-promoted Mn/Na₂WO₄/SiO₂ catalyst for oxidative coupling of methane at atmospheric pressure. Journal of Natural Gas Chemistry, 2010, 19(1): 47–53

19 Nguyen T N , Seenivasan K , Nakanowatari S , Mohan P , Tran T P N , Nishimura S , Takahashi K , Taniike T . Factors to influence low-temperature performance of supported Mn-Na₂WO₄ in oxidative coupling of methane. Molecular Catalysis, 2021, 516: 111976

20 Ortiz-Bravo C A , Figueroa S J , Portela R , Chagas C A , Bañares M A , Toniolo F S . Elucidating the structure of the W and Mn sites on the Mn-Na₂WO₄/SiO₂ catalyst for the oxidative coupling of methane (OCM) at real reaction temperatures. Journal of Catalysis, 2022, 408: 423–435

21 Yildiz M , Aksu Y , Simon U , Kailasam K , Goerke O , Rosowski F , Schomäcker R , Thomas A , Arndt S . Enhanced catalytic performance of Mn_xO_y-Na₂WO₄/SiO₂ for the oxidative coupling of methane using an ordered mesoporous silica support. Chemical Communications (Cambridge), 2014, 50(92): 14440–14442

22 Kiani D , Sourav S , Baltrusaitis J , Wachs I E . Oxidative coupling of methane (OCM) by SiO₂-supported tungsten oxide catalysts promoted with Mn and Na. ACS Catalysis, 2019, 9(7): 5912–5928

23 Arndt S , Otremba T , Simon U , Yildiz M , Schubert H , Schomäcker R . Mn-Na₂WO₄/SiO₂ as catalyst for the oxidative coupling of methane. What is really known? Applied Catalysis A, General, 2012, 425: 53–61

24 Yıldız M . Mesoporous TiO₂-rutile supported Mn_xO_y-Na₂WO₄: preparation, characterization and catalytic performance in the oxidative coupling of methane. Journal of Industrial and Engineering Chemistry, 2019, 76: 488–499

25 Baidya T , Van Vegten N , Verel R , Jiang Y , Yulikov M , Kohn T , Jeschke G , Baiker A . SrO·Al₂O₃ mixed oxides: a promising class of catalysts for oxidative coupling of methane. Journal of Catalysis, 2011, 281(2): 241–253

26 Sourav S , Wang Y , Kiani D , Baltrusaitis J , Fushimi R R , Wachs I E . Resolving the types and origin of active oxygen species present in supported Mn-Na₂WO₄/SiO₂ catalysts for oxidative coupling of methane. ACS Catalysis, 2021, 11(16): 10288–10293

27 Aydin Z , Zanina A , Kondratenko V A , Rabeah J , Li J , Chen J , Li Y , Jiang G , Lund H , Bartling S . . Effects of N₂O and water on activity and selectivity in the oxidative coupling of methane over Mn-Na₂WO₄/SiO₂: role of oxygen species. ACS Catalysis, 2022, 12(2): 1298–1309

28 Sun N , Zhang J , Ling L , Zhang R , Jia L , Li D , Wang B . Effect of different oxygen species on the oxidative coupling of methane over TiO₂ catalysts. Applied Catalysis A, General, 2023, 650: 118998

29 Sourav S , Kiani D , Wang Y , Baltrusaitis J , Fushimi R R , Wachs I E . Molecular structure and catalytic promotional effect of Mn on supported Na₂WO₄/SiO₂ catalysts for oxidative coupling of methane (OCM) reaction. Catalysis Today, 2023, 416: 113837

30 Yildiz M , Simon U , Otremba T , Aksu Y , Kailasam K , Thomas A , Schomäcker R , Arndt S . Support material variation for the Mn_xO_y-Na₂WO₄/SiO₂ catalyst. Catalysis Today, 2014, 228: 5–14

31 JiangZ CGongHLiS B. Methane activation over Mn₂O₃-Na₂WO₄/SiO₂ catalyst and oxygen spillover. In: Studies in Surface Science and Catalysis. Elsevier, 1997, 481–490

32 Yan B , Lin L , Wu J , Lei F . Photoluminescence of rare earth phosphors Na_0.5Gd_0.5WO₄:RE³⁺ and Na_0.5Gd_0.5(Mo_0.75W_0.25)O₄:RE³⁺ (RE = Eu, Sm, Dy). Journal of Fluorescence, 2011, 21(1): 203–211

33 Tiyatha W , Chukeaw T , Sringam S , Witoon T , Chareonpanich M , Rupprechter G , Seubsai A . Oxidative coupling of methane—comparisons of MnTiO₃-Na₂WO₄ and MnO_x-TiO₂-Na₂WO₄ catalysts on different silica supports. Scientific Reports, 2022, 12(1): 2595

34 Xu B , Yang Y , Xu Y , Han B , Wang Y , Liu X , Yan Z . Synthesis and characterization of mesoporous Si-modified alumina with high thermal stability. Microporous and Mesoporous Materials, 2017, 238: 84–89

35 Kidamorn P , Tiyatha W , Chukeaw T , Niamnuy C , Chareonpanich M , Sohn H , Seubsai A . Synthesis of value-added chemicals via oxidative coupling of methanes over Na₂WO₄-TiO₂-MnO_x/SiO₂ catalysts with alkali or alkali earth oxide additives. ACS Omega, 2020, 5(23): 13612–13620

36 Abdalla Z E A , Li B , Tufail A . Preparation of phosphate promoted Na₂WO₄/Al₂O₃ catalyst and its application for oxidative desulfurization. Journal of Industrial and Engineering Chemistry, 2009, 15(6): 780–783

37 Vamvakeros A , Matras D , Jacques S D , di Michiel M , Middelkoop V , Cong P , Price S W , Bull C L , Senecal P , Beale A M . Real-time tomographic diffraction imaging of catalytic membrane reactors for the oxidative coupling of methane. Catalysis Today, 2021, 364: 242–255

38 Ismagilov I , Matus E , Kuznetsov V , Kerzhentsev M , Yasnik S , Larina T , Prosvirin I , Navarro R , Fierro J , Gerritsen G . Effect of preparation mode on the properties of Mn-Na-W/SiO₂ catalysts for oxidative coupling of methane: conventional methods vs. POSS nanotechnology. Eurasian Chemico-Technological Journal, 2016, 18(2): 93–110

39 Bayer V , Podloucky R , Franchini C , Allegretti F , Xu B , Parteder G , Ramsey M G , Surnev S , Netzer F P . Formation of Mn₃O₄ (001) on MnO (001): surface and interface structural stability. Physical Review B: Condensed Matter and Materials Physics, 2007, 76(16): 165428

40 Scofield J H . Hartree-Slater subshell photoionization cross-sections at 1254 and 1487 eV. Journal of Electron Spectroscopy and Related Phenomena, 1976, 8(2): 129–137

41 Elkins T W , Hagelin-Weaver H E . Characterization of Mn-Na₂WO₄/SiO₂ and Mn-Na₂WO₄/MgO catalysts for the oxidative coupling of methane. Applied Catalysis A, General, 2015, 497: 96–106

42 Kim G J , Ausenbaugh J T , Hwang H T . Effect of TiO₂ on the performance of Mn/Na₂WO₄ catalysts in oxidative coupling of methane. Industrial & Engineering Chemistry Research, 2021, 60(10): 3914–3921

43 Gu S , Oh H S , Choi J W , Suh D J , Jae J , Choi J , Ha J M . Effects of metal or metal oxide additives on oxidative coupling of methane using Na₂WO₄/SiO₂ catalysts: reducibility of metal additives to manipulate the catalytic activity. Applied Catalysis A, General, 2018, 562: 114–119

44 Schwarz H . Chemistry with methane: concepts rather than recipes. Angewandte Chemie International Edition, 2011, 50(43): 10096–10115

45 Zanina A , Kondratenko V A , Lund H , Li J , Chen J , Li Y , Jiang G , Kondratenko E V . Performance-defining factors of (MnO_x)-M₂WO₄/SiO₂ (M = Na, K, Rb, or Cs) catalysts in oxidative coupling of methane. Journal of Catalysis, 2023, 419: 68–79

46 Wang P , Zhao G , Liu Y , Lu Y . TiO₂-doped Mn₂O₃-Na₂WO₄/SiO₂ catalyst for oxidative coupling of methane: solution combustion synthesis and MnTiO₃-dependent low-temperature activity improvement. Applied Catalysis A, General, 2017, 544: 77–83

47 Jodaian V , Mirzaei M . Ce-promoted Na₂WO₄/TiO₂ catalysts for the oxidative coupling of methane. Inorganic Chemistry Communications, 2019, 100: 97–100

48 Li S B . Oxidative coupling of methane over W-Mn/SiO₂ catalyst. Chinese Journal of Chemistry, 2001, 19(1): 16–21

49 Wang Y , Sourav S , Malizia J P , Thompson B , Wang B , Kunz M R , Nikolla E , Fushimi R . Deciphering the mechanistic role of individual oxide phases and their combinations in supported Mn-Na₂WO₄ catalysts for oxidative coupling of methane. ACS Catalysis, 2022, 12(19): 11886–11898

50 Si J , Zhao G , Lan T , Ni J , Sun W , Liu Y , Lu Y . Insight into the role of Na₂WO₄ in a low-temperature light-off Mn₇SiO₁₂-Na₂WO₄/cristobalite catalyst for oxidative coupling of methane. ACS Catalysis, 2022, 13(2): 1033–1044