郑兆宇, 徐波, 曾傲楠, 王安杰, 刘颖雅, 孙志超, 王瑶. Ni/SiO2协同DBD等离子体催化甲烷干重整性能研究[J]. 燃料化学学报(中英文). DOI: 10.19906/j.cnki.JFCT.2024022
引用本文: 郑兆宇, 徐波, 曾傲楠, 王安杰, 刘颖雅, 孙志超, 王瑶. Ni/SiO2协同DBD等离子体催化甲烷干重整性能研究[J]. 燃料化学学报(中英文). DOI: 10.19906/j.cnki.JFCT.2024022
ZHENG Zhaoyu, XU Bo, ZENG Aonan, WANG Anjie, LIU Yingya, SUN Zhichao, WANG Yao. DBD plasma-assisted dry reforming of methane over Ni/SiO2[J]. Journal of Fuel Chemistry and Technology. DOI: 10.19906/j.cnki.JFCT.2024022
Citation: ZHENG Zhaoyu, XU Bo, ZENG Aonan, WANG Anjie, LIU Yingya, SUN Zhichao, WANG Yao. DBD plasma-assisted dry reforming of methane over Ni/SiO2[J]. Journal of Fuel Chemistry and Technology. DOI: 10.19906/j.cnki.JFCT.2024022

Ni/SiO2协同DBD等离子体催化甲烷干重整性能研究

DBD plasma-assisted dry reforming of methane over Ni/SiO2

  • 摘要: 分别采用沉积沉淀法(DP)和浸渍法(IMP)制备Ni/SiO2催化剂前体,前体经H2还原得到Ni/SiO2-DP和Ni/SiO2-IMP。对所制备的催化剂进行X射线衍射、X射线光电子能谱、N2吸附-脱附、化学吸附、傅里叶变换红外、透射电镜和拉曼光谱表征,并考察其与介质阻挡放电等离子体(DBD)协同催化甲烷干重整(DRM)制合成气反应性能。研究结果表明,相较于Ni/SiO2-IMP,Ni/SiO2-DP因其较小的Ni颗粒尺寸、Ni与载体的强相互作用以及对反应物分子较强的吸附活化能力,具有更高的催化活性和稳定性。对Ni/SiO2-DP制备条件考察结果表明,H2等离子体还原(PR)的Ni/SiO2-DP-PR比程序升温还原(TPR)的Ni/SiO2-DP-TPR具有更高的催化活性。沉积沉淀时间为10 h,H2等离子体还原时间为30 min时,CH4和CO2转化率分别为72.5%和78.2%,H2和CO选择性分别为86.7%和94.2%,能量利用率为4.36 mmol/kJ。

     

    Abstract: Dry reforming of methane reaction(DRM) utilizes both CH4 and CO2 greenhouse gases to convert them into synthesis gas (H2 and CO), which can be further synthesized into value-added chemicals such as hydrocarbons or liquid oxygen-containing compounds. The traditional thermal method for catalyzing DRM reaction often uses Ni-based catalysts. And it requires high reaction temperature (>700 ℃). The high temperature leads to sintering and carbon deposition of Ni-based catalysts, as well as low energy efficiency, which limits the application of this reaction. Dielectric barrier discharge plasma (DBD) can synergistically drive the reaction with Ni-based catalysts at low temperature, thereby addressing the drawbacks of thermal catalysis. The key of this technology is to develop catalysts that have synergistic effects with plasma and strong resistance to carbon deposition. Therefore, this paper uses nickel phyllosilicate as precursor and H2 plasma reduction to prepare highly dispersed Ni-based catalyst, which synergistically catalyze the DRM reaction with DBD plasma. Nickel phyllosilicate was prepared by deposition-precipitation method, and Ni/SiO2-DP was obtained after calcination and reduction. Ni/SiO2-IMP was prepared by impregnation method. The prepared catalysts were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, N2-adsorption-desorption, chemisorption, Fourier transform infrared, transmission electron microscope, thermogravimetric analysis and Raman spectra. The catalytic performance for dry reforming of methane (DRM) to synthesis gas was investigated in the dielectric barrier discharge(DBD) reactor. The research results indicate that Ni/SiO2 -DP has higher catalytic activity and stability, which benefits from its smaller Ni particles size, stronger interaction between Ni and support, and stronger adsorption ability for the reactants, compared with Ni/SiO2 -IMP. The CH4 and CO2 conversions of Ni/SiO2-DP are 61.7% and 70.0%. The selectivities of H2 and CO are 86.9% and 94.3%, and H2/CO is 0.92. The CH4 and CO2 conversions of Ni/SiO2-IMP are 44.2% and 28.4%. The selectivities of H2 and CO are 62.7% and 42.4%, and H2/CO is 1.48. After stability testing, the catalysts were characterized by TG. The weight loss of Ni/SiO2- IMP is 84.45%, while the weight loss of Ni/SiO2-DP is only 34.06%. The preparation conditions of Ni/SiO2 -DP were investigated. The results show that the Ni/SiO2-DP-PR from H2 plasma reduction(PR) exhibits higher catalytic activity than the Ni/SiO2-DP-TPR from temperature programmed reduction(TPR). DBD plasma reactor contains a large number of high energy particles, including H atoms, excited state H atoms, and ionic hydrogen (H+, H2+, H3+). The reduction ability of H2 plasma is much higher than that of temperature programmed reduction. H2 plasma can fully reduce the precursor at low temperature, avoiding the aggregation of Ni particles caused by temperature programmed reduction, resulting in smaller Ni particles size in the obtained catalyst. When the deposition-precipitation time is 10 hours, the catalytic activity of the catalyst is optimal. When the deposition-precipitation time is less than 10 hours, the content of Ni in the catalyst is relatively low, resulting in low activity. When the deposition-precipitation time exceeds 10 hours, long deposition-precipitation time may lead to an increase in the crystallinity and nickel phyllosilicate particles size. As the deposition-precipitation time increases, the deposition components gradually block the pores and reduce the specific surface area of the catalyst, resulting in a decrease in the catalytic activity of the catalyst. Under optimal preparation conditions, the conversions of CH4 and CO2 are 72.5% and 78.2%. The selectivities of H2 and CO are 86.7% and 94.2%, and H2/CO is 0.89. The energy efficiency is 4.36 mmol/kJ.

     

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