Mn 协同调控 NiAl 催化剂抗积碳及合成气优化的反应机制

Reaction Mechanism of Mn-Mediated Synergistic Modulation of Anti-Coking Properties and Syngas Optimization in NiAl Catalysts

摘要

针对“双碳”目标下碳酸盐热解高碳排放问题，本文采用溶胶-凝胶法制备了 Mn 掺杂改性的 NiMnAl 催化剂，该催化剂在 750 ℃表现出显著的性能提升：CH₄ 转化率由 NiAl 的 11%提高至 16%，H₂/CO 体积比趋近于 1，积碳量降低 20% 以上。表征分析表明，Mn 掺杂后可以通过电子结构重排和原位形成 MnO₂ 活性相，从而提升晶格氧迁移率，使比表面积由 NiAl 催化剂的 63.215 m²/g增至 NiMnAl 催化剂的 82.087 m²/g，孔隙结构得到优化。协同作用机制使催化剂兼具高活性与抗积碳特性，热重分析表明积碳的起始氧化温度降低，通入少量 O₂ 后积碳量进一步减少。X 射线衍射（XRD）与 BET（Brunauer-Emmett-Teller）比表面积测试表明，通氧工况可有效缓解积碳对孔隙结构的破坏。本研究为高效抗积碳催化剂的开发及工业应用提供了理论依据。

Abstract

Aiming at the problem of high carbon emissions during carbonate pyrolysis under the dual-carbon strategy, Mn-doped modified NiMnAl catalysts were prepared via the sol-gel method in this work. The as-prepared NiMnAl catalysts exhibited remarkable performance improvement at 750 ℃. Compared with pristine NiAl catalysts, the CH₄ conversion rate increased from 11% to 16%, the H₂/CO volume ratio approached 1, and the carbon deposition decreased by more than 20%. Characterization results revealed that Mn doping enhanced lattice oxygen mobility through electronic structure rearrangement and thein-situ formation of MnO₂ active phases. Meanwhile, the specific surface area increased from 63.215 m²/g of the NiAl catalyst to 82.087 m²/g of the NiMnAl catalyst, accompanied by an optimized pore structure. The synergistic mechanism endows the catalyst with high catalytic activity and excellent carbon deposition resistance. Thermogravimetric analysis showed that the initial oxidation temperature of carbon deposits decreased, and the carbon deposition was further reduced by introducing a small amount of O₂. X-ray diffraction (XRD) and BET（Brunauer-Emmett-Teller） specific surface area measurements indicated that oxygen-introducing conditions can effectively alleviate the damage of pore structure caused by carbon deposition. This study provides a theoretical basis for the development and industrial application of high-efficiency anti-carbon-deposition catalysts.

关键词

碳酸盐热解 / 催化还原 / NiMnAl 催化剂 / Mn 掺杂 / 积碳抑制 / CH₄ 干重整

Key words

carbonate pyrolysis / catalytic reduction / NiMnAl catalyst / Mn doping / carbon deposition inhibition / dry reforming of methane

参考文献

[1] Intergovernmental Panel on Climate Change. Climate Change 2021 — The Physical Science Basis: Working Group I Contribution to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [M]. Cambridge: Cambridge University Press,2022:287-422.

[2] Intergovernmental Panel on Climate Change. Climate Change 2013 — The Physical Science Basis: Working Group I Contribution to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change[M]. Cambridge: Cambridge University Press,2014:659-740.

[3] SUN S, LYU Z, QIAO Y, et al. Integrated CO₂ capture and utilization with CaO—alone for high purity syngas production[J].Carbon Capture Science & Technology, 2021, 1:100001.

[4] KABANOV A A. Effect of iron oxides on the kinetics of the thermal decomposition of CaCO₃•0.17H₂O[J].Russian Journal of Physical Chemistry, 2002, 76(9):1559-1561.

[5] HU J, HONGMANOROM P, CHIRAWATKUL P, et al. Efficient integration of CO₂ capture and conversion over a Ni supported CeO₂—modified CaO microsphere at moderate temperature[J].Chemical Engineering Journal, 2021, 426(1):130864.

[6] SHI S L, ZHANG Y X, PAN Y, et al. Hydrogenation of CaCO₃ to CH₄ catalyzed by NiCO₃ [J].Chemical Engineering Journal, 2024, 485:150012.

[7] CHOI D S, KIM N Y, YOO E, et al. Enhanced coke resistant Ni/SiO₂@SiO₂ core—shell nanostructured catalysts for dry reforming of methane: Effect of metal—support interaction and SiO₂ shell[J].Chemical Engineering Science, 2024, 299(1):120480.

[8] 窦本浩, 杜锦标, 胡兆一, 等. 基于镍铝催化剂的碳酸盐加氢热解还原反应特性研究 [J].华东理工大学学报 (自然科学版), 2025, 51(1):10-22.

[9] PRABHAKAR J K, KUMAR R, RAY K, et al. Understanding the role of Mn in Ni—Mn/Al₂O₃ and Ni₃Fe—Mn/Al₂O₃ catalysts for enhanced CO₂ methanation activity[J].Journal of Environmental Chemical Engineering, 2025, 13(1):115-233.

[10] SHADRAVAN V, BUKAS V J, GUNASOORIYA G T K K, et al. Effect of manganese on the selective catalytic hydrogenation of CO_x in the presence of light hydrocarbons over Ni/Al₂O₃: An experimental and computational study[J].ACS Catalysis, 2020, 10(2):1535-1547.

[11] KOHN M P, CASTALDI M J, FARRAUTO R J. Auto—thermal and dry reforming of landfill gas over a Rh/γAl₂O₃ monolith catalyst[J].Applied Catalysis B: Environmental, 2010, 94(1):125-133.

[12] BAKER R T K, BARBER M A, HARRIS P S, et al. Nucleation and growth of carbon deposits from the nickel catalyzed decomposition of acetylene[J].Journal of Catalysis, 1972, 26(1):51-62.

[13] NGUYEN D L T, TRAN A V Y, VO D V N, et al. Methane dry reforming: A catalyst challenge awaits[J].Journal of Industrial and Engineering Chemistry, 2024, 140:169-189.

[14] HUANG L, LI D, TIAN D, et al. Optimization of Ni—based catalysts for dry reforming of methane via alloy design: A review[J].Energy & Fuels, 2022, 36(10):5102-5151.

[15] WANG L, WANG F. Design strategy, synthesis, and mechanism of Ni catalysts for methane dry reforming reaction: Recent advances and future perspectives[J].Energy & Fuels, 2022, 36(11):5594-5621.

[16] OU Z, RAN J, QIU H, et al. Understanding the role of Co segregation on the carbon deposition over Ni—Co bimetal catalyst in dry reforming of methane[J].Separation and Purification Technology, 2024, 333:125868.

[17] SHAH M, AL MESFER M K, DANISH M, et al. Study on the effect of promotors in CO₂ utilization for syngas production via dry reforming of methane over Co—MOX/TiO₂—Al₂O₃ (MOX=La, Ce, Mg, and K) catalysts[J].Fuel Processing Technology, 2024, 257:108089.

基金资助

国家重点研发计划(2022YFA1504701)

国家自然科学基金(22208104)

上海市科委启明星项目扬帆专项(22YF1410300)

上海市教委晨光计划(21CGA35)